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.
My latest blog post: Sheeple: Are they succumbing to fake news, misinformation, and propaganda. (posted 2025-09-24). My latest podcast: OJB's Podcast 2029-09-09 Kiwi Values.