Apple TV stuck in login loop
I was trying to login to iTunes on my Apple TV, I would enter my email, password and when I entered the 2 factor authentication code it would loop back to the start asking for email again. I read many other posts with the same issue but no real fix. I called Apple Support and they had me do the following.
Logout of iTunes on Apple TV.
Reset Apple TV
Log in to iTunes after reboot
It worked for me !