Can't login to site using Yubikey via Firefox

Hello, about 3 - 4 weeks ago I used my Yubikey to login to a secure site via Firefox. Yesterday I again tried to login to the same site using my Yubikey and failed. An error messaged appears as per the screen shot.

I then tried another two browsers (Edge, Vivaldi) and succeeded in using both browsers to login using my Yubikey. I also was able to login to (using my Yubikey) the same site via Firefox on my Windows laptop without issue. My two Firefox apps are not linked in any way.

Has anyone else come across this issue and know of a way to fix the problem?

I manged to find and lose a reddit post that discussed the same problem. In the end the reddit author said it was a windows issue and fixed via Settings > Privacy & Security > Passkeys (very bottom of the page). The author said he granted permission to Firefox to use the Yubikey via the "Let apps create and use passkeys" drop down. I attempted this, but the dropdown doesn't open (or is empty), regardless of the status of the "Passkey access" button which was initially on. In the "recent activity" drop down I can see requests from Firefox, Edge and Vivaldi.

I have also reached out to the Firefox community for help on the subject.