iCloud sign in issues Apple TV

Hi,

my issue is with an Apple TV

model A1468

software 7.2.2

I cannot sign into either nine or my wife’s iCloud accounts. I’ve talked on the phone with Apple support for 2 hours and could not resolve the issue.

Things ive tried: restart, reset, restore, restart modem, restart router, unplug apple TV (in specific sequence), use my password and add two factor authentication code on the end no spaces. I was told by Apple support that it is a problem with my router, howeve, the Apple TV is the only device that fails to sign in (my I’d works with my compute, iPad and wife’s iPhone).

Any help would be appreciated.