AirPlay no longer working MacBook Pro to Apple TV - requests code but will not work

Up until tonight I've had no problems with Airplay from my Macbook (13-inch, Late 2013) to my Apple TV.

Now when I try airplay the Macbook asks for a 4 digit code, which comes up on the Apple TV. I enter it and get the message get the message:

"Could not connect to Apple TV"

I tried typing an incorrect code to see what would happen and it just keeps requesting the code, so there is communication between devices.

I have checked:

They are both on the same network.

Both signed into same apple ID.

Restarted the Apple TV

Restarted the MacBook

Restarted the router.

Both are up to date with software (tvOS 10.0.1 & macOS Sierra 10.12.1)

I have gone into Airplay > Security on the Apple TV and it is set to "None." It should not be asking for the passcode.

I have tried to Airplay from my iPhone to the Apple TV and that works fine (but does ask for code despite 'Security' set to 'None', but the Macbook to the Apple TV doesn't get that far.

I am finding this extremely frustrating as this is the main reason I bought the Apple TV. If anyone has any advice it would be greatly appreciated.