Our realm has recently experienced lines of chunks being deleted and replaced with new chunks (in the attachments are some visual examples)
Our realm has recently had the gamerules changed without uploading a new map or manually changing the settings (example: coordinates are normally on, but one day they were switched off unexpectedly)
Our realm has recently completely reset to a day 0 zero map of the same seed.

Our realm has been lingering on a file size just under 4 gigabytes for a while now, and that is what I suspect is causing the issues (I think the size goes over 4gb occasionally and it causes the issue?). Our realm has reset to day 0 before, but the other two issues are completely new.