Problem with ftp access FW 2.11.140 Mirror Gen 2 12TB

i have many problems to access the ftp-server on my My Cloud Mirror Gen . 2 with FW 2.11.140. All rights are set in the WD GUI-Dashboard. If i will access the ftp, the login goes right, but after there it is impossible to see the directory content (yes it has content) and it is also impossible to write/store new files or create directories.

ftp> mkdir test
550 Sorry, users are not allowed to create directories

Btw., i have another My Cloud Mirror 12 TB Gen 2. with FW 2.11.133 and this works fine.
It likes be wrong permissions, but where has them to set? Both Mirrors has the same permissions in the Dashboard. Only the one with the FW 2.11.140 makes trouble.

Any ideas? Firmware Bug or User-Bug?
Thanks for help.

If all settings have been double-checked and another unit is allowing you to access your files using the same method then it could be a difference in firmware behavior. Did you try a factory reset (System only) in case there is an internal configuration issue?