User in shared folder with all permissions cannot simply move folder in on v2.3.3

[ssnd292]

A user who has full access to a shared folder and is in my circle, wants to move a folder to a different location in that shared folder, but the app and online panel say its "forbidden"

This is the error code he recieves on the Win10 app

23.04.2018 10:24:30, Projekt C Saboteur/Screenshots, Nextcloud,Blacklisting fortsetzen: Error transferring https://****/Projekt C Saboteur/Screenshots - server replied: Forbidden

I double checked all permission and he even is an administrator in my circle, but he still cannot move nore delete files.