6.12.0.Rc2 and ZFS Z1 (Raid5) Cache - can't delete empty Folders

Hello.

I don't know if I found a 6.12.0-RC2 oder ZFS bug or if it is a problem in my configuration.

When I used 6.11.5 stable, I used 3 pieces of 2TB SSD combined with BTRFS als a Cache for several SMB shares.
There I copied from external Win-PC to the share, and the files were buffered in this Cache ("cachesam").
Then i could automatically (mover) or manually (mc, krusader oder File Plugin) move the fiiles and directories from the cache to the Disks in the array.

Now I changed to 6.12.0-RC2, deleted this cache, created it with ZFS Z1 (Raid5) new.

Here I do also copy files from the same extrenal Win-PC to the smb share, it gets buffered on the cache ("cachesam").
Then I try to manually move the directory/folders including the files to the array.
The files get moved, but mc and even the file manager plugin can't move or even delete the now empty DATA or AEV folders on the cache ("cachesam").

If technical info is neccesary: see my Footer, this is my 2nd System (Shipon).

Here some Pics:
Screenshot 1: mc can not move the DATA Directory to the Array. The files in it were moved.
Screenshot 2: FileManager Plugin tries to delete the empty DATA folder. but after I klick proceed and reload the cachesam Directory DATA still exists.
Screenshot 3: Emptied Directory(Folder)  /mnt/cachesam/DATA  shown in Filemanager plugin and mc simultaneous.