If you're streaming to an Apple TV, you need to mirror the entire iPhone or iPad. If you just see a video on the screen, your Apple TV is just playing the video at the speed it was filmed while you ride at your own speed in FulGaz.
You need to either make sure you're mirroring your iPhone or iPad, or use the FulGaz Apple TV app.
If you have a 4th Generation Apple TV or newer, please install FulGaz directly on your Apple TV. This will give you much better performance and video quality and you can use your existing subscription.