After further testing in 26.20.27 Preview, I have finally found the root cause of the issue. It is not the command blocks that suffer. It is not functions or scripts that suffer, it's not the chat menu that suffers. It is the /gamemode command itself that just, well silently fails, and being broken there in somehow cheat enabled worlds with the hardcore flag set. However, it claims to succeed.

Outputs if run from the command block:

Your gamemode has been updated to <gamemode>

[<command block hovernote, or ! if none is present>: Set <PLAYERNAME>'s game mode to <gamemode>]

Outputs if run from chat: (needs cheats enabled to work)

Your gamemode has been updated to <gamemode>

Set own game mode to <gamemode>

Apparently , /gamemode works to change gamemode in somehow cheat enabled hardcore in Java. This is unlike Bedrock Edition’s somehow cheat enabled hardcore, where the /gamemode command itself silently fails there, which is working as intended there. MCPE-187646

Can confirm

This is because the tag used to store the dimension of a map is a signed byte tag named dimension, which is susceptible to overflow from positive values above 127. Custom dimension numeric integer ids begin from 1000. Upgrading the tag to an integer tag will fix the issue.

Invalid, your game is modified, and bug reports are only accepted in English.

It happens consistently. If the bug tracker can’t properly support april fools snapshots, and neither can the feedback site or Minecraft Support, then where is the official channel to report an April Fools snapshot bug?

Can confirm, my game crashed too.

Actually, the April Fools snapshot version (26w14a) also released as well. Invalid.

Can confirm in 26.20.22 Preview.

This is because the minecraft:absorption attribute is capped at 16, according to either DefaultMax or Max float tags.

This also happens when the filled maps from the cartographer village chests enter your inventory. Once the maps enter your inventory, you don’t have to look at them, all these map files get created anyway and consume the world size.

Can still confirm in 26.20.22 Preview with the NBT editor to inspect data.

The master ticket got resolved as Fixed even though not all the subtitles listed are fixed, but this bug regarding an individual subtitle,

MCPE-233114

Is still technically open as of 26.20.22. Normally Mojang would prefer if the reports are split up for easy tracking, but in this case, a master ticket was decided…

Can confirm in 26.20.22 Preview.

Can confirm in 26.20.22 . This is because there is no json code to spawn a spider with effects according to the latest spider json code:

{
  "format_version": "1.26.0",
  "minecraft:entity": {
    "description": {
      "identifier": "minecraft:spider",
      "is_summonable": true,
      "is_spawnable": true,
      "spawn_category": "monster"
    },
    "components": {
      "minecraft:attack": {
        "damage": 2
      },
      "minecraft:behavior.avoid_mob_type": {
        "entity_types": [
          {
            "filters": {
              "all_of": [
                {
                  "test": "is_family",
                  "subject": "other",
                  "value": "armadillo"
                },
                {
                  "test": "enum_property",
                  "subject": "other",
                  "domain": "minecraft:armadillo_state",
                  "value": "unrolled"
                }
              ]
            },
            "max_dist": 6,
            "sprint_speed_multiplier": 1.2
          }
        ],
        "priority": 2
      },
      "minecraft:behavior.float": {
        "priority": 1
      },
      "minecraft:behavior.hurt_by_target": {
        "entity_types": [
          {
            "filters": {
              "operator": "!=",
              "test": "is_family",
              "subject": "other",
              "value": "breeze"
            }
          }
        ],
        "priority": 1
      },
      "minecraft:behavior.look_at_player": {
        "look_distance": 6,
        "priority": 7
      },
      "minecraft:behavior.mount_pathing": {
        "priority": 5,
        "target_dist": 0.0,
        "speed_multiplier": 1.25,
        "track_target": true
      },
      "minecraft:behavior.random_look_around": {
        "priority": 7
      },
      "minecraft:behavior.random_stroll": {
        "priority": 6,
        "speed_multiplier": 0.8
      },
      "minecraft:breathable": {
        "suffocate_time": 0,
        "total_supply": 15
      },
      "minecraft:can_climb": {},
      "minecraft:collision_box": {
        "height": 0.9,
        "width": 1.4
      },
      "minecraft:conditional_bandwidth_optimization": {},
      "minecraft:despawn": {
        "despawn_from_distance": {}
      },
      "minecraft:experience_reward": {
        "on_death": {
          "expression": "query.last_hit_by_player ? 5 : 0",
          "version": 13
        }
      },
      "minecraft:health": {
        "max": 16,
        "value": 16
      },
      "minecraft:hurt_on_condition": {
        "damage_conditions": [
          {
            "cause": "lava",
            "damage_per_tick": 4,
            "filters": {
              "subject": "self",
              "test": "in_lava"
            }
          }
        ]
      },
      "minecraft:is_hidden_when_invisible": {},
      "minecraft:jump.static": {},
      "minecraft:loot": {
        "table": "loot_tables/entities/spider.json"
      },
      "minecraft:movement": {
        "value": 0.3
      },
      "minecraft:movement.basic": {},
      "minecraft:nameable": {},
      "minecraft:navigation.climb": {
        "can_path_over_water": true
      },
      "minecraft:physics": {},
      "minecraft:pushable": {
        "is_pushable": true,
        "is_pushable_by_piston": true
      },
      "minecraft:renders_when_invisible": {},
      "minecraft:rideable": {
        "family_types": [
          "baby_undead"
        ],
        "seat_count": 1,
        "seats": {
          "position": [
            0.0,
            0.54,
            -0.1
          ]
        }
      },
      "minecraft:type_family": {
        "family": [
          "spider",
          "monster",
          "mob",
          "arthropod"
        ]
      }
    },
    "component_groups": {
      "minecraft:spider_angry": {
        "minecraft:angry": {
          "calm_event": {
            "event": "minecraft:become_calm",
            "target": "self"
          },
          "duration": 10,
          "duration_delta": 3
        },
        "minecraft:behavior.leap_at_target": {
          "must_be_on_ground": false,
          "priority": 4,
          "yd": 0.4
        },
        "minecraft:behavior.melee_box_attack": {
          "track_target": true,
          "priority": 3
        }
      },
      "minecraft:spider_hostile": {
        "minecraft:behavior.nearest_attackable_target": {
          "attack_interval": {
            "min": 5,
            "max": 5
          },
          "must_see": true,
          "entity_types": [
            {
              "filters": {
                "any_of": [
                  {
                    "test": "is_family",
                    "subject": "other",
                    "value": "player"
                  },
                  {
                    "test": "is_family",
                    "subject": "other",
                    "value": "snowgolem"
                  },
                  {
                    "test": "is_family",
                    "subject": "other",
                    "value": "irongolem"
                  }
                ]
              }
            }
          ],
          "priority": 2
        },
        "minecraft:environment_sensor": {
          "triggers": {
            "event": "minecraft:become_neutral",
            "filters": {
              "operator": ">",
              "test": "is_brightness",
              "value": 0.49
            }
          }
        },
        "minecraft:on_target_acquired": {
          "event": "minecraft:become_angry"
        }
      },
      "minecraft:spider_bogged_jockey": {
        "minecraft:addrider": {
          "riders": [
            {
              "entity_type": "minecraft:bogged"
            }
          ]
        },
        "minecraft:rideable": {
          "family_types": [
            "skeleton"
          ],
          "seat_count": 1,
          "seats": {
            "position": [
              0.0,
              0.325,
              -0.1
            ]
          }
        }
      },
      "minecraft:spider_wither_jockey": {
        "minecraft:addrider": {
          "riders": [
            {
              "entity_type": "minecraft:wither_skeleton"
            }
          ]
        },
        "minecraft:rideable": {
          "family_types": [
            "skeleton"
          ],
          "seat_count": 1,
          "seats": {
            "position": [
              0.0,
              0.54,
              0.0
            ]
          }
        }
      },
      "minecraft:spider_neutral": {
        "minecraft:environment_sensor": {
          "triggers": {
            "event": "minecraft:become_hostile",
            "filters": {
              "operator": "<",
              "test": "is_brightness",
              "value": 0.49
            }
          }
        },
        "minecraft:on_target_acquired": {
          "event": "minecraft:become_angry"
        }
      },
      "minecraft:spider_jockey": {
        "minecraft:addrider": {
          "riders": [
            {
              "entity_type": "minecraft:skeleton"
            }
          ]
        },
        "minecraft:rideable": {
          "family_types": [
            "skeleton"
          ],
          "seat_count": 1,
          "seats": {
            "position": [
              0.0,
              0.54,
              0.0
            ]
          }
        }
      },
      "minecraft:spider_stray_jockey": {
        "minecraft:addrider": {
          "riders": [
            {
              "entity_type": "minecraft:stray"
            }
          ]
        },
        "minecraft:rideable": {
          "family_types": [
            "skeleton"
          ],
          "seat_count": 1,
          "seats": {
            "position": [
              0.0,
              0.54,
              0.0
            ]
          }
        }
      },
      "minecraft:spider_parched_jockey": {
        "minecraft:addrider": {
          "riders": [
            {
              "entity_type": "minecraft:parched"
            }
          ]
        },
        "minecraft:rideable": {
          "family_types": [
            "skeleton"
          ],
          "seat_count": 1,
          "seats": {
            "position": [
              0.0,
              0.325,
              -0.1
            ]
          }
        }
      }
    },
    "events": {
      "minecraft:become_angry": {
        "add": {
          "component_groups": [
            "minecraft:spider_angry"
          ]
        }
      },
      "minecraft:entity_spawned_with_default_jockey": {
        "filters": {
          "any_of": [
            {
              "test": "is_daytime",
              "value": false
            },
            {
              "test": "is_underground",
              "value": true
            }
          ]
        },
        "add": {
          "component_groups": [
            "minecraft:spider_jockey",
            "minecraft:spider_neutral"
          ]
        }
      },
      "minecraft:become_calm": {
        "remove": {
          "component_groups": [
            "minecraft:spider_angry"
          ]
        }
      },
      "minecraft:become_hostile": {
        "add": {
          "component_groups": [
            "minecraft:spider_hostile"
          ]
        },
        "remove": {
          "component_groups": [
            "minecraft:spider_neutral"
          ]
        }
      },
      "minecraft:entity_spawned_with_biome_specific_jockey": {
        "first_valid": [
          {
            "filters": {
              "all_of": [
                {
                  "test": "is_daytime",
                  "value": false
                },
                {
                  "test": "is_snow_covered",
                  "value": true
                },
                {
                  "test": "is_underground",
                  "value": false
                }
              ]
            },
            "add": {
              "component_groups": [
                "minecraft:spider_stray_jockey",
                "minecraft:spider_neutral"
              ]
            }
          },
          {
            "filters": {
              "all_of": [
                {
                  "test": "is_daytime",
                  "value": false
                },
                {
                  "test": "is_underground",
                  "value": false
                },
                {
                  "any_of": [
                    {
                      "test": "has_biome_tag",
                      "value": "swamp"
                    },
                    {
                      "test": "has_biome_tag",
                      "value": "mangrove_swamp"
                    }
                  ]
                }
              ]
            },
            "add": {
              "component_groups": [
                "minecraft:spider_bogged_jockey",
                "minecraft:spider_neutral"
              ]
            }
          },
          {
            "filters": {
              "all_of": [
                {
                  "test": "is_daytime",
                  "value": false
                },
                {
                  "test": "is_underground",
                  "value": false
                },
                {
                  "test": "has_biome_tag",
                  "value": "desert"
                }
              ]
            },
            "add": {
              "component_groups": [
                "minecraft:spider_parched_jockey",
                "minecraft:spider_neutral"
              ]
            }
          },
          {
            "filters": {
              "test": "has_biome_tag",
              "value": "nether"
            },
            "add": {
              "component_groups": [
                "minecraft:spider_wither_jockey",
                "minecraft:spider_neutral"
              ]
            }
          },
          {
            "trigger": "minecraft:entity_spawned_with_default_jockey"
          }
        ]
      },
      "minecraft:become_neutral": {
        "add": {
          "component_groups": [
            "minecraft:spider_neutral"
          ]
        },
        "remove": {
          "component_groups": [
            "minecraft:spider_hostile"
          ]
        }
      },
      "minecraft:entity_spawned": {
        "randomize": [
          {
            "randomize": [
              {
                "trigger": "minecraft:entity_spawned_with_biome_specific_jockey",
                "weight": 80
              },
              {
                "trigger": "minecraft:entity_spawned_with_default_jockey",
                "weight": 20
              }
            ],
            "weight": 1
          },
          {
            "add": {
              "component_groups": [
                "minecraft:spider_neutral"
              ]
            },
            "weight": 99
          }
        ]
      }
    }
  }
}

Still an issue in 26.20.22 Preview

Still an issue for resolved reports and comments created, where the user still cannot do:

• Edit their own resolved reports (For example, I am the reporter of MCPE-233116, and it got resolved as fixed even though it’s clearly not fully. )

• Edit or delete their own created comments.

This is unlike the old bug tracker.

Fixed for:

• Open reports the reporter has created.

This bug is not completely fixed. Since the reporter of this bug can’t edit resolved reports, it will be in a comment:

Subtitles like these are still unfixed in 26.20.22, for example:

1. When “Elytra rustle” message is “Leather armor rustles”. (Caused by the player equipping elytra)

2. When “Block placed” message is “Anvil landed”. (Only caused by placing any anvil)

3. When “Cauldron hisses” message is “Fire extinguished“. (Caused by mixing liquids unsuccessfully in a cauldron, like mixing potions)

I noticed it was in options.txt under the name:
gfx_vsync:1

The fact it is set to 1 by default makes it a real FPS limiter. All players should be given the option to disable VSync.

Bug reports are only accepted in English.

Can confirm in Preview 26.20.20. More behaviours are tested with the old dyes.