Server is crashing randomly

So, as of late, my server has been crashing for no reason to be seen. This is a 1.13.2 Vanilla Server with on ly 3 people tops playing at a time, the three of us are getting very annoyed with this and now random weird things are happening to the world (random chunks of land appearing where they shouldn't be). It's getting to the point where none of us want to be on the server at all... and I tried to find a reason for it but there's no crash log at all...