I've recently noticed the following behaviour on the Apple TV app:
When watching a live channel that has been paused, so you're behind "live". If you try to catch up to "live" by jumping forward a few times, when it gets to "live" it jumps back to the start of the buffer instead, making it very hard to easily return to watching live, without existing and re-opening the channel to clear the buffer.
I presume this is a regression in a recent update, as I've not noticed it before.