During gameplay, usually in a process-heavy moment; (E.g. Respawn, Nightfall when mobs spawn, or chunk load during exploration…) the game will lock up and release periodically, with lock-ups increasing in magnitude causing the server to quickly become unplayable.
Initially this sounds like a problem with my PC, or possibly internet connection. Understandably so.
This bug cannot be recreated in any other minecraft server, even when stress-testing the PC with shaders or other process-heavy tests.
Trying to investigate causes; I noticed that ping rate for your server is surprisingly high. Reaching 800+ms during these spikes before crash.
To remedy this; I lowered my chunk view distance. This helps, but the spikes still occur frequently.
Another test I tried was loading a graphics-heavy game and playing multiplayer on servers located far away, and during the game switching between processes to try and create a hiccup. Nothing. Servers resumed, and connection was not lost or even slowed.
I will continue testing for root causes, but I believe the bug is with your servers during a large loadout, like during a respawn.
Let me know if other users are having similar issues as well.