Using the same remote on more than 1 atv

I noticed that sometimes I can use a remote on a different unit (not the original one that the remote is synced with) and it won’t work on a different unit (again not the original)

Why is this?

It’ s possible your second ATV is synced to a diffrent remote

 

You can use any Apple Remote to unpair Apple TV from a remote. Note: If you lose the Apple Remote that you paired with Apple TV, a replacement remote will not work until you unpair Apple TV from the lost remote.

Press and hold the Menu and Previous/Rewind buttons on a white Apple Remote for 6 seconds, or the Menu and Left buttons on an aluminum Apple Remote for 6 seconds.

You can also use these steps:

  1. Choose Settings > General > Remotes from the Apple TV main menu.
  2. Choose Unpair Apple Remote.

When you’ve successfully unpaired a remote, Apple TV displays a broken chainlink symbol () above a picture of a remote. You can now pair Apple TV with a different remote.