Here is a video below showing what's happening. This isn't on just shark tank, it's on other recordings as well. It's like once it gets close to the end of the show and I can't watch the rest of it I will exit out. And I come back to it starting back to the front. Then I have to remember where I left off. This also happens on iOS as well.
This is by design and working correctly.
Channels marks it as watched once you’ve watched a certain percent of the show. This doesn’t happen if you stop it mid way.
If it required a full 100% of watching to mark as watched, nothing would get marked as watched.