Extreme server TPS lag with 2+ players (Contains debug!)

Extreme TPS lag (and regularly crashing) if 2+ players are logged in and not rendering same chunks, saw not many of these reports had debug files. Hope this helps!

NOTE there ARE a few small datapacks on the server, if needed I can disable them and rerun the debug.
The lag / crashing was extremely prevalent even before the datapacks were added.