Why is YouTube shutting down?

Question

YouTube

There is a premium subscription to YouTube. I turn on the video and minimize the application, the video plays in a small window, as it should be. I turn on the game (Team Fight Tactics) and when I'm in the game in the main menu, everything is OK, the video in the small window goes on and the game works, but as soon as the game is found (collected team) and the download starts, YouTube closes and closes the window. How can I make sure to leave both the game and the video?

youtube vanced tried and doesn't help with that.