That’s good news!
Hm, from Bitwarden’s side, the FIDO2 PIN is only asked when you register the security key as 2FA-“passkey”… when you authenticate with it, then the PIN isn’t requested. In fact, there is a Feature Request about making it optional to get asked for the PIN: Optionally require PIN code when using hardware key / security key (FIDO2 / "passkey"-2FA)
When you get asked for the PIN when authenticating, then that is probably due to some setting/configuration of the security key. - Did you enable always_UV? (see here: https://www.token2.com/site/page/fido2-security-keys-pin-protection-when-and-why-pin-is-asked-)
… though, that doesn’t sound like you enabled always_UV… ?!?