My realm keeps rolling back when everyone logs off, and it becomes idle.
The next time someone logs in, it will have rolled back a certain amount of time.

Almost like an entire realm backup worth of time back.
It rolls back everything, from inventories, players, and world changes. 

This happens almost every time the realm seems to become idle, when no one is on. 
Otherwise it keeps on working fine. So maybe every time it goes "to sleep" or "shuts down" when not in use?

I can test more if anything more is needed from me. 
I will try to figure out exactly how much time it rolls back, and if I can trigger it on command.