Do you have PIN configured? As I understand it, I think Microsoft asks for a credential with "User Verification", which requires a pin code, password or biomet

Do you have PIN configured? As I understand it, I think Microsoft asks for a credential with "User Verification", which requires a pin code, password or biometric recognition. If the Yubikey is used a second factor (instead of the only factor as with passwordless), you can be more lax and ask for "User Presence", which only requires touching the key. ref: https://w3c.github.io/webauthn/#test-of-user-presence https://w3c.github.io/webauthn/#test-of-user-presence