Server Crashes Randomly even with watchdog disabled

This began very early on in the server. We would be playing and it would crash and kick everyone off while displaying we were all still online. I noticed when it went to make a backup the server would crash from WatchDog. I disabled WatchDog and it seemed to help for a little bit but now the server will just crash randomly. Every time I try to fix this or read up on it it's a Spigot or Modded issue. This is a Vanilla server, however. I thought it was maybe the MineOS software so I uploaded the files and ran it on a Mac Mini running 10.15.7. The server acted the same. I tried redownloading the Jar. The same issue, I even tried running it on an old Windows computer I had in a drawer. Same issue.