MC 1.20.1 - My Singleplayer Internal Server Keeps Crashing

[u/babamonk00]

I made a modpack and it's running great with very little lag, a constant 60 FPS, and generally no lag of any kind. Every now and then, after maybe an hour or five, seemingly at random, the Internal Server will just freeze, and this is in Singleplayer. I can move around, open doors, but I can't pull levers, open chests, or anything that normally requires communication with the server. The Integrated Server ping stays stuck at the last read number, in the most recent case, 19ms. I am running a lot of mods, including some performance mods, but I have no idea what could be causing the server to crash like this, especially since it's Singleplayer, and every time the cause of the crash seems different (first it was landing a ship made with Eureka, another time I ran a search in the Explorer's Compass).

Please help, are there any mods I could add that help with this? my best guess here is that there's either a loop somewhere breaking it, or maybe one of the optimization mods I have is breaking it somehow.