FWIW, Facebook, Dropbox and Github use Fido2 just fine on mobile (Chrome browser). You don't need the TOTP fallback for Facebook on mobile browser (though anno

FWIW, Facebook, Dropbox and Github use Fido2 just fine on mobile (Chrome browser). You don't need the TOTP fallback for Facebook on mobile browser (though annoyingly they'll still always send you the code via SMS, if you haven't disabled). I suppose it's possible that their app has issues with FIDO2, and maybe that's why you had to fallback to TOTP. But yeah, 4 services (including Google), out of all the ones that I use... The track record for supporting FIDO2 is underwhelming. It's especially annoying that you cannot set up backup FIDO2 keys in AWS, which means that I won't rely on it.