@LemonyIdle Welcome to the forum!
When you log in to the web vault… and when you then go to Settings → Security → Two-step login → Passkey → “Manage”… do you see “Migrated from FIDO” behind your registered YubiKeys here (in my screenshot, the “Migrated from FIDO” is not there):
If you see “Migrated from FIDO”, you should re-register your YubiKeys.
(and maybe see this thread FIDO U2F keys are being phased out in 2025 - make sure to replace those in time - the last posts are the most “accurate” ones 
)