ipad mini 3 iOS 12.5

Hello.

On my iPad mini 3 all Game Apps crashing after nearly 30 secs. The games stop playing Music and after 2 seconds i got an black screen also for 2 seconds. After that im back to my Homescreen. But the Game is still open in the background.

Anybody an Idea? And mayby wich settings are to be made in generall Settings?

What i have tried: Force Restart, Restore over DFU. Everytime the Same.

But Apples own Apps like Apple Music is working fine. And the Device by its self also works good.