Mobs returning from the end gateway spawn in the overworld at y=-64

Steps to reproduce:

• Generate a flat world

• Remove all but the last layer of bedrock and remove a ring of bedrock, say from 5-block radius around 0,0.

• Build an end portal off to the side, go to the end, and kill the dragon.

• Grab some spawn eggs. I prefer chickens because they float down

• Send a few through (like 10), then follow them through the portal.

• Hear them suffocate in the bedrock once as the world loads, then quickly look below the bedrock through the ring you cleared around 0,0 and watch in horror as the chickens hit the damage grid below the world and die.

Expectation:

• Ideally that any mob travelling through the end portal would spawn at whatever the highest solid block is at 0,0. I believe this is Java’s behaviour, so this is by definition a parity issue.

• Alternatively, the previous buggy behaviour, which is well documented on YouTube, where mobs would spawn at over 32,000 and a relog/leave the area and come back would bring them down to 512 or alternatively that they start at 512, and fall from 512 down and you’d have to use a water block to catch them. Although in the cases of shulkers, only if a boat is sent through the portal as well, and they end up in the boat, falling otherwise, they stay up in the air forever.

Notes from research:

• pay attention to the coordinates that you first spawn at in a normal world; these coordinates aren’t just the world making sure you don’t spawn in a hole, they actually seem to affect where mobs come through the end portal too. For the current normal seed I’ve testd, this turned out to be x=-13 z=21, but in the flat world it was literally just 0,0.

• For shulkers, you can clear out an area around the expected coordinates above y=-59. Then send them through. As Shulkers will teleport up when taking damage, they should end up in the pocket you created if in doubt as to the coordinates, just clear a pocket from x/y -30 to x/y +30 that’s 2-3 blocks tall standing at -59. You will want to use invis potions, boats, and happy ghasts to air lift them out of the hole, or boats and a 2x2 or 3x3 bubble column.

• For all other mobs (except the allay that travels with you very closely even through the end portal)… Realistically, you’re probably not sending anything other than shulkers through the end portal, but if, for some reason, you need to, the only way I’ve found to catch them currently is to dangle boats through broken bedrock into the void.

• For items thrown through the portal the only way to get them currently would seem to be to dangle hopper minecarts into the void in advance. Apparently, items are coming into the world at -64.000 or very close to because the natural item elevator effect through solid blocks doesn’t happen and the items end up in the void this would also explain why mobs are falling through as typically mobs stuck in a block won’t fall through they’ll jump up and out of the block they’re clipping into..