It worked great until yesterday, and today, I cannot get it to work. The video below illustrates the problem:

https://buzzheavier.com/3jekkdqj1fu2

I have tried:

1. Clearing the cache of both HW Fido2 Provider and IronFox
2. Rebooting
3. Installing Key Driver BT Kunizoft
4. Disabling uBlockOrigin, Cookie Banner Blocker and Enhanced Tracking Protection

Any ideas?

Perhaps try Authnkey which is more recently updated.
If that doesn't work then some details like which security key you are using and over which protocol (USB or NFC) would be good to know.

Thanks! It worked! :D

I was/am using it through NFC. Although I did try to connect it through USB too, but to no avail. Maybe I just should've been more careful with when HW Fido2 Provider was last updated. IronFox's website recommended it...