Unexpected error unlocking the encrypted volume 99999

Hi,
In a Debian12 + Spyder5-env, with the udev-rules installed, I’m trying to open the existing crypto container (ext4) using the command “nitropy storage open-encrypted”. The user PIN is asked but, after a while, a critical error is thrown. (I can’t upload the log-file yet).

Any ideas on how to open (and read from/write to) a crypto container from the Storage using Python3 code? All hints appreciated.

V/R,
Daniel