Create a new world.
Load only chunks around (0,0)
/tp @s 0 ~ 0 /setworldspawn 0 ~ 0
Summon entity with UUID 0-0-0-0-0
/summon marker 0 0 0 {UUID:[I;0,0,0,0]}
Unload 0-0-0-0-0 entity
/tp 0-0-0-0-0 99999 0 0
Summon another entity with UUID 0-0-0-0-0
/summon marker 0 0 0 {UUID:[I;0,0,0,0]}
✔ Unable to summon entity due to duplicate UUIDs
Pause the game about three times.
Summon another entity with UUID 0-0-0-0-0
/summon marker 0 0 0 {UUID:[I;0,0,0,0]}
❌ Summoned new marker
Linked issues
relates to 1
Attachments
Comments 1

Can confirm in 21w39a.