I had this problem with Dashlane after they suddenly changed their policies, though with a regular password. My solution? Out of frustration I developed my own password manager. Eventually I was able to recover the password from my email provider though. But at that point I had no more nails left.
I had the same issue with LastPass a few years ago. When I reinstalled my OS they decided to lock me out of my account because they thought I was a different person. The only way through is e-mail verification. Guess where that email's password was stored in?
Sorry, I can't remember. They suddenly lowered the amount of clients a few years ago. This locked me out of my e-mail client. Since 2FA updates were sent to my e-mail it lead to a bit of tail-biting. Pretty much the same problem can happen with a passkey. Either way this blew away a lot of the trust I used to have in password managers, so out of frustration I coded my own as a backup that can digest Dashlane output so I never need to rely only on them ever again.