how to sign out of my apple tv on sony tv
cant sign in to my appletv on my television with new details which are ok with all other mac/ pads etc?
If you have 2 Factor Authentication enabled on your account did you get a verification code and enter that?
See if anything here helps. If necessary, you can use account recovery as explained in the link at bottom of the article.
Verification code - how to get one and sign in with two-factor authentication.