The issue:
I've been playing for a few days with some friends on a server created on my machine, everything was going well until today (09/08/2023) the server started crashing for no apparent reason. Even previously explored regions of the map are crashing. At first my character seems to be the one responsible for the crash, but he doesn't have any new items compared to yesterday. The times the crash happened I was flying with an Iron Jetpack in Overworld, close to our base.

Only separately installed module: Chunk Pregen.

Crash reports:

crash-2023-09-08_02.41.18-server.txt
crash-2023-09-08_01.39.06-server.txt
crash-2023-09-08_01.49.24-server.txt
crash-2023-09-08_02.06.38-server.txt
crash-2023-09-08_02.15.08-server.txt

And two crash reports of me trying to run the world in a singleplayer environment:

crash-2023-09-08_03.28.32-server.txt
crash-2023-09-08_03.21.14-server.txt