Why won't my Elite 2 controller Connect to Xbox One?

Hi.

I recently bought an Xbox Elite 2 controller. It was purchased new.

It connects to my PC, but won't connect to the Xbox One in the house. Sometimes it connects and I can make 2 clicks before it is not functioning. I have tried power cycling the controller, turning the Xbox off and on. Connecting via provided USB-C cable. Sometimes the rumble registers but buttons are not usable. It says my controller needs an update but doesn't allow me to update the controller. And the controller does not show up on the connected devices in the System Preferences.

Please send help or advise if I should return and repurchase.

Thanks

:)