full screen display disappears for TV app and can't figure out how to get it back

It's on a different "space". Just press control and right arrow. You'll get the full screen video back.

The full screen video is playing on a different "space". Press control and right arrow and it will take you to the video.

That's weird. I just tested and have the same situation.

My screen stays full, but only sound continues after I open an app and I cannot get the movie back.

I'll be giving Apple feedback; that's about all we can do.

Apple will have most substandard product, even a basic app which we can code in sleep, allow apple, they will duck it up and I am sure, they will present it as a feature.

its irritating, to see a duckinbg basic app not work, not on other devices, on their own devices for duck sake.

I just unsubscribed from AppleTV+. Much simpler that way.

Sounds silly, but it takes a reboot of the machine to get your viewing window back. That's what worked for me.

Worked for me. Thanks