But you can show them the video posted on this site, right? Just put it on your phone as if it were done on your machine.
I haven't heard of this happening on the 15 which is strange. There are things that lead me to believe that it's a software issue, but, if it is, then why isn't it seen on other models? It might be due to more graphics horsepower on those other models of course.
I suggested this last time but they said that they had to see the fault with their own eyes in order to authorise a hardware fix. Will try again next week, but it’s a pain in the backside to keep having to go back to the store. I don’t know why they closed down some of the third party repair places which gave people more options which were often easier to get appointments with and also easier to get to.