Continuing Question: Both "Save and Fill addresses" and "Save and fill payment methods" boxes are checked. "Require device sign in..." box is not checked. Address Fill works. When I try to auto fill credit card, credit card number fills but then disappears.

I have this same problem, on several different sites, including sites where it used to work. Very annoying bug, they need to fix it soon.

Thank you, brads2, for your feedback. Good to know I'm not the only one. And me also--it used to work just fine.

They know it's not working. https://bugzilla.mozilla.org/buglist.cgi?quicksearch=credit+card

Thank you, jonzn4SUSE. I appreciate your response!

One of the entries at the link supplied by jonzn4SUSE above actually contains the following fix that worked for me:

1. Go into your Firefox Settings => Privacy & Security tab on the left => scroll down to Payment Methods 2. Delete all cards that are stored 3. Add the cards again (literally the identical data you just deleted)

Referenced support link is: https://bugzilla.mozilla.org/show_bug.cgi?id=1876347