On Apple TV , we no longer have the option to press “play” on an episode - only “add to up next.” The only episodes we can press play on are the first episodes of the first season of a show.

Same for me. There's no onscreen play button, and any episode >1 just toggles between in/out of Up Next. I wanted to watch episode 10 of Echo 3 tonight! WTF Apple?!

Same issue, can’t watch the next episode of “Severance,” only see “Add to up next.”

I think I've got a workaround for the broken playback problem, but this is on a physical Apple TV box. I don't know if it will work on the iPhone/iPad/Mac/other apps.

Go to Settings > Apps > TV > Home Screen, then click until "Top Shelf" reads, "Up Next."

This moves the "Up Next" thumbnails to the top of the screen, and when you click the "Select" pad or the "Play/Pause" button, the episode plays.