Google Nest Community

I have a random issue. A few times I’ve experienced a blue square pop up in the middle of streaming. I don’t watch a lot but the past couple of times it happened when watching a soccer game on Paramount Plus. Any ideas what it means?

I have the newest Chromecast with Google TV.While streaming a show from the native apps, the picture dims (into the background but continues to play) and a blue rectangle appears on the screen. At this time the remote doesn't control the app anymore....