Can you try defaulting the master code locally at the panel? I am curious if this is simply an issue with the code not being synced properly.
Changing it locally to 1234 may help trigger a zone scan if the SEM reverted the expected Master code to 1234. Changing it online wouldn’t do anything if the SEM had the wrong code, which sounds like it may have been the initial error that occurred here.
To update the master code on the panel locally:
Enter your current master code.
Press 8.
Press 02.
Enter the default code 1234.
Re-enter the default code 1234. The keypad will beep once to let you know that the code has been changed.
After, see if the same errors occur. If not you should then be able to sync the code to your desired value by changing it online.