Don't know if you still have your issue, but what you describe is just a Display misconfiguration.
Go to your Settings > Display: you'll see both of the two screens (the one of your laptop and the TV screen), and then you can choose either to extand your workspace on the second screen (the current configuration you're describing: you have a display aside the other one, so you can move your windows & mouse from one screen to another switching by passing through the edge) or to mirror your displays (checkbox "Mirror displays") if you want to see the same thing on the TV screen that on your laptop.
Hoping that helped