I have a NucBox G5 and I think I'm impacted by the same issue. The next boot after the autoupgrade to 12.2.1, the system boots into the Kodi interface and after a few seconds, hard locks. I have not been able to access the system to perform any kind of diagnostics because of this hard lock, but did manage somehow to get the attached screen shot to appear once. I don't know if it's useful but wanted to share whatever I could to help troubleshoot this issue.