Help request

Problem

I have the problem that everytime i restart the server, the items in my backpack disappear. It also happens when i log out.
What I have tried

I looked into the config files, but didn't find anything that would enable backpackclear after logout (only inactivity, but that's disabled). It may be a bug, either it's not storing or there is a conflict between the plugin and multiverse etc..
(Actually, while typing the message i had an idea (cuz i had trouble with the "PerWorldPlugins" plugin) and i fixed this issue before actually posting it, but i thought i could post it, just in case sb had the same issue :3)