Any solution to this?

just wait for it to be fixed. I have seen a bug report and I am sure it was assigned, so without looking for it again. Just wait a month or two. Poke again if it does not get fixed as I am relying entirely on my memory here and it is getting old.

Yeah, I'm having this issue now with v102.8 in Feb 2023. So, how long, exactly, are we supposed to wait? Not being able to add a field to the Address Book app seems like a pretty big issue. But that's just me.

Even VALID URLs entered on the CardDAV host and synced to TB show up when Edited in TB as INVALID and which, as a result, you then can't update, save, or edit that Card from then on, unless you delete the "invalid" URL. This should be a REALLY SIMPLE fix. Apparently, the verification code (why is there even any?) for the Website entry field was written by a first grader, or at the least, someone who failed Programming 101.

Man, I'm so sick of Mozilla's continued gestapo approach to forcing "security" and "rightness" on its user base it makes me want to give up on it after 20 years and finally give in to CHROME. Ugh. I can't even LOG IN to this web site using autofill from Bitwarden, but have to copy and paste TWICE for the UN and PW. WTF? Mozilla is the ONLY site that requires that. Do these guys intentionally try to make things difficult and their users miserable? I keep asking myself why I didn't just spend the $200 on Outlook and chose to futz with Thunderbird in the first place instead.

I found the solution to TB's Address Book issue: Use CardBook instead ((https://gitlab.com/CardBook/CardBook). It works great. Shows different Google Contacts Labels correctly, and will actually let you save an invalid URL. Basically, it just works.