Did some googling on this one, saw that people way back in 1.14.1 had the same issue. Game crashes when a player enters certain chunks, so far just 48 18. Running a multiplayer server with just the 4 of us right now and some minor datapacks that add a few more variants to structures. Perhaps this is the issue? All the datapacks are supposedly ready for 1.19.

We were originally running Forge (if that matters) and switched to Fabric to see if the crash would continue, and it does. Going to try without either next and see if that helps, but the existence of this type of crash way back in 1.14.1 leads me to believe it isn't a Forge or Fabric issue.