I think this happened to me last night with an ad for Moana 2 playing automatically. I just assumed I accidentally hit a button. I was on the home screen but it enlarged and played in the basically the top quarter of the screen. I hit Close and it closed.

Also, the Netflix app is absolute garbage on the TCL Roku TVs. Constantly freezes and crashes, sometimes while not even try to rewind or pause/resume. It just decides its had enough and causes the TV to restart lol.

Waterfox is on Android too! I just installed it on both Mt PC and phone.