Actually, existing passkeys were fine, but you couldn't add a new passkey to your account.

You now can again.

I suspect I'm really the only one using a passkey to login instead of my username and password anyway - but if you are fed up of keep entering a username and password to login I'd highly advise checking out passkeys. There are applications around (such as Bitwarden which I highly recommend) which will create and store passkeys for sites - and DearDiary is compatible with these.

At least, it is again now I've fixed it 😀