Using /execute to teleport between dimensions causes levels to disappear until returning to the departing dimension, or relogging into the server.

This happens to any users logged into the server that use built-in commands to navigate between dimensions, either through a datapack I wrote that implements in-game access to the command or via directly calling /execute as @s in minecraft:overworld run tp @s 0 75 0 from the nether.

The server owner has provided a debug log recorded while executing said command, and I have attached it here, along with my original datapack that uses this mechanic.

It appears to be server-based.