I swear they've done this before, but in either case you can turn it off in settings. Took me about two times of it happening before I did.
What's worse is if you select the highlighted video it starts over rather than just continue.
turned it off immed!
Who in the right mind is using the Youtube app on android TV? SmarttubeNext is THE shit:
https://github.com/yuliskov/SmartTubeNext