I'm getting a similar, and possibly related, issue - Named mobs (especially) are dying with the message "Fell out of the world" when the chunk they're in is loaded. This makes me think entities are loading before the terrain is finished loading, and are thus falling into the void. This also implies it's not a network issue (as it's all happening server-side) but related to slow chunk loading.
Anaerin
I'm getting a similar, and possibly related, issue - Named mobs (especially) are dying with the message "Fell out of the world" when the chunk they're in is loaded. This makes me think entities are loading before the terrain is finished loading, and are thus falling into the void. This also implies it's not a network issue (as it's all happening server-side) but related to slow chunk loading.
Server Version: 1.18.2