Fixed the issue myself. I reset my remote and it came back to life and can now control everything I once could.
Press and hold Digit 1 and Digit 6 on your TalkTalk remote at the same time for 3 seconds. During this time the red LED will remain off. After 3 seconds the red LED will turn on, then enter 981 on the remote. The red LED will blink to confirm it's reset and you should be able to use it.