this is the question dougumbarger asked in 2022. There does not appear to be a solution posted I now have the same problem. Especially noted with ticketing sites like Ticket master, Eventbrite.

Firefox has my credit card information and it shows up in a window when I go to pay for something, but when I click on the credit card I want to pay with, it won't autofill. In Settings, the box to autofill is checked. This has worked a hundred times before, but stopped working a few months ago. How do I get the autofill to start working again