Apple passkey rejected "Can't verify your account." Is there any way to delete/recreate this passkey?

For the last four days, any attempt to sign into an Apple website (appstoreconnect.apple.com, developer.apple.com/account or account.apple.com) with my passkey is failing with the message "Can't verify your account. Try again or continue with password."

I can still log in with email+password+code but I would prefer to fix my passkey.

I don't know if this is due to iOS 18.1.1, 18.2 or adding new devices to my account. All happened in a short space of time.

With non-Apple passkeys, I would delete them from the Passwords app but my Apple passkey doesn't appear in Passwords.

Is there any way to recreate an Apple passkey? Or is there a known issue affecting passkeys that is under investigation? Or are there other steps I can take to resolve the situation?