Unable to log in to Apple TV app on smart TV

Hi, I am no longer able to log in to apple tv on our smart tv. i go through all the steps and then get the message "can't log you in now, try again later". I have reset my password., same message. I can log in via the xbox but i just want to be able to log straight in via the tv. I used to be able to do that. do you think my tv is too old now? any assistance greatly appreciated