Hello Arne, please excuse my late response and thank you very much for your help! :) I've tried to revert but it fails and since I don't know whether my data will be lost when reinstalling from iso every release (maybe I would need to ream my disk every time), I've got myself a used Dell Latitude where it worked fine. Maybe I should stick with Intel to learn and switch to ARM64 / RISC-V when I halfway know what I'm doing.. Many thanks again and best regards, Alex