If changing printer settings no longer works because the system starts requesting the lpadmin password try this command in Terminal:
dseditgroup -o edit -p -a admin -t group _lpadmin
This adds the admin user back to the lpadmin group and changes should then be possible.
I usually write a blog post about once a week. The latest post can be viewed here: Are We the Baddies?: Maybe you should ask yourself: are we the baddies? (posted 2025-11-24 at 17:01:10). I do podcasts too!. You can listen to my latest podcast, here: OJB's Podcast 2025-11-06 Democracy v Bureaucracy: It's not left versus right which I am complaining about: it is bureaucracy versus democracy!.