I just install the beta profile and the Feedback application popped up. When I tried to sign in, the keyboard didn’t popped up! Same as Signing in on Facetime here.
Unable to Sign in on Feedback Assistant iPadOS 14
I have no idea why this is happening, it is the exact same thing for me, except I have the ios 14 betas. It may be an intentional thing, I heard Everything Apple Pro say something about the os being faster because the feedback assistant isn't running. I would like to get on it, but it won't let me click on the sign-in button.