iPad Air 3rd generation blank screen issue

So I’ve had this issue for awhile now after just a month out of my warranty. Every day there are times when I hit the power button or the home button to unlock my iPad Air 3rd gen and it just comes up with a black screen. If I push the buttons enough times it eventually shows me my Lock Screen and I can get in and sometimes have to wait until it run out of battery. I’ve already tried the following:

hard reset

resetting from a backup

resetting the iPad from scratch

Also I visited my local apple store because I found out that this iPad model got issue and they do offer a Service Program for 2 years after it was purchased. He check the hardware but he sees nothing wrong so the technician installed a fresh OS and hoping it would fix the problem (it works for a week then the issue came back) that’s pretty much it. I will set up my second appointment and have them take a look again. Any help would be much appreciated.