AirPlay stops playing (like pause) -

My Apple TV 4k is connected via ethernet wire. The devices (source) are all up-to-date and connected via 5GHz wifi.

No matter if I use an iphone 8plus, iphone 11pro or ipad. AirPlay stops after a few minutes always same interval) just like if someone had pushed pause. The frozen picture is shown on the TV.

I have to switch back the view to the device (AirPlay button on device). Then it shows the picture there and ATV shows it's screen. The movie is not playing, but the pause symbol is shown in the video controls.

I now need to press pause, switch back to AirPlay and then press play to continue on the TV.

If I just press pause and play it will remain frozen on the TV screen.

If I then press AirPlay to switch back to the iPad, it starts to continue to play the movie there.

Really wired.

The event typically happens every 4-8 Minutes.

No matter if I stream Netflix, Disney or if I have the movie downloaded locally.