The weird thing is: Yubikey was the only option for me in Gmail. Only after I associated a Yubikey with it, was I able to also use an authenticator app. Does a

The weird thing is: Yubikey was the only option for me in Gmail. Only after I associated a Yubikey with it, was I able to also use an authenticator app. Does anyone know if this is normal behaviour, and if so, what the reasoning behind it is?