Windows desktop version of Bitwarden did not request my FIDO U2F authentication

I’ve been using Bitwarden (premium) for a few weeks now and am generally pleased.
I have a FIDO U2F key enabled and it works when I re-LOGin.

When I installed the Windows desktop version of Bitwarden, however, it INITIALLY requested for my AUTHY authenticator code, which worked fine, but did not require me to press the FIDO U2F button.

I THEN LOGGED OUT, both the desktop version and the browser version, and tried to log in again. It only required my password and did not require EITHER my Authy authenticator NOR my FIDO U2F (prefered) authentication.

How do I get the desktop exe version of Bitwarden to recognize and request the FIDO U2F authenticator button to be pressed whenever I LOG in?

NOTE: I am NOT speaking of the lock out process… I AM speaking of re LOGGING in.

FIDO U2F is only supported on browser extensions and web vault. You’ll need to use one of the other methods on desktop, such as Authy.

Just to confirm my understanding, is it possible to successfully sync a desktop Bitwarden app using just the pass phrase for a user, even if a given account has U2F enabled? Shouldn’t the desktop app just be unable to auth if the 2fa type is U2F?

No. You cannot log in to a client app if you only have a 2FA provider enabled that isn’t compatible with it, such as U2F. This is why you can enabled multiple 2FA providers.