Lines on screen of iPad Mini 3

Hi,

I have got a problem with the screen of my iPad Mini 3. There are thin, parallel lines on the right side of the screen. It started with an area of just a few mm into the screen, then it went to several cm. Two days ago it went up to covering half the screen and also showing the home screen above the app that was running, making half of the screen unreadable (but it reacted properly to touches).

The lines do not show on screenshots.

The weird thing: I had exactly the same problem on another iPad Mini 3. I made a new setup (back to factory settings), no change. Went to the Genius Bar in the nearest Apple Store, they said they had never seen that before. Then I bought a new device, my current iPad Mini 3. That was in spring 2018. It was fine for some months but in September it started to develop the same problem. It did not really fall down and it did not get wet etc.

I am getting a bit frustrated as this is the second one and I am not keen on buying a third one in less than a year. Is there anyone who has had the same problem?

Any help beyond "probably it fell down, go to the Apple Store and ask for help" would be greatly appreciated! I am living in a remote place and the nearest authorised dealer is about 1000 km away ...