I have set up to use Fido, Authy and email as 2fa methods and all three work faultlessly on my pc using the Firefox extention. I have two tablets running the Android app (android 8 and android 13).
Both tablets react the same. They both go directly to the FIDO2 WebAuthn page without the option of being able to select other method remain there for ever awaiting validation of FIDO2 token.
Reading thru the posts I see reference to tapping the top right corner for additional options. this flashes by instantly not allowing access and defaults to FIDO2 WebAuthn as described above.