Multiple crashes and consecutive error codes in-game: WEASEL, BABOON, and PLUM

I've been dealing with some extremely frustrating and intermittent issues in Marathon recently. They've mostly cropped up in Cryo Archive, but I've had issues in Dire Marsh as well. The issues are broad and inconsistent, but most of the time they're characterized by "connecting to Marathon servers" messages, WEASEL and BABOON error codes, and the game outright freezing and crashing. The game often also has difficulty reconnecting me to a disconnected run, oftentimes booting me back to the reconnect screen a second time or outright crashing again.

I've updated my drivers, tried another internet connection, and verified my game files, and none of these solutions have helped or fixed the problem. This has caused me to lose a significant amount of loot, and while I'm not here to beg to get it back, I'd like to know if anyone else has similar problems and where I might start trying to fix it.