Hello, and Thank You for choosing JustAnswer.comMy name is ***** ***** I am reviewing your question now, please stand by for 1 or 2 minute for reply.
So....you have to UPDATE yoru password ***** your APPLE TV.
Your Apple TV uses your Apple ID.
And if you change your Apple ID password......then your Apple TV doesnt know that.....and you have to UPDATE the Apple ID password.
Then it shoudl work again.