EmilS

So, @Mainfrezzerwas right. 
In the past my Mover copied all files from my cache appdata to my array as a backup. 
After uninstalling Mover Tuning, the Mover actually moved the files. 
Appdata of Containers that where stopped/unused were completly moved and all running containers crashed, because the Mover moved files that the containers used not so often. 
Luckily I had backup from the Backup / Restore Appdata Plugin. 
After restoring all files into a new folders, changing all containers to use those now folders, everything works again. 
My data is not gone, nextcloud and dbs are running.
Perfect. 
Man, that was scary.