I have similar problems with my server. The vehicles wont save locations + they loss items on server restart. I had to shut down my servers so the players of my server would stop complaining about losing everything on mandatory server restarts.
I have witnessed a player hacking on the server. We have banned him, along with his IP. We're sorry this couldn't be prevented sooner. I personally think battleye needs to be fixed to detect hacks at this level for this mod.