Ask for a second factor (OTP) even if username is not valid

Hi,

I am playing around with Debian 10, OpenSSH and Google Authenticator PAM module.
So far so good.
Almost everything works as expected.
I am using password and OTP.
PAM is configured to ask for OTP even if the password is not valid.
Now I found out SSHD is not going to ask for OTP if the username is not valid.
That is useful for intruders, to guess usernames, but absolutely not what i want.

I thought it would be a good idea, if the system behaves the same, and ask for OTP, no mater if the password is valid or not.
Am I wrong?
Is there a way to ask for OTP even if the user is not valid?

Thanks for your answers.