Can confirm
Still an issue in 1.21
Still an issue in 1.20.5
Still an issue for 24w09a. This seems to be a major bug for hardcore worlds because if you jump into the void, then your world is gone forever. The Mojang priority must be reassigned to very important because of what I said.
Unfortunately, if you change the game mode to creative, it must have cheats on, which means you can't earn any achievements. If you enable cheats in your world, you can't get any of them again.
How is this exactly happening? It never spawns outside of the range. If you know the reason that is happening, then add it to the description.
I went into Minecraft 1.20.2, and clicking multiplayer doesn't crash the game. Maybe someone should resolve the issue to invalid.
You would need to have cheats enabled for it to work.
Unable to reproduce the bug in 1.21.4.
It gives me the message "Data pack validation failed!"