iPhone 6se has unresponsive screen

My issue began on Dec 4, 2015 and since then i have been inside an apple store 6 times, I am on phone number 4 and my problem persists. My problem began on a one year old iPhone 6Plus but carried over to a 6se (I switched on the theory the problem is unique to the 6Plus). Roughly every 4 to 6 weeks I wake up to a phone that has an unresponsive screen, it will 'boot' itself every 4 or 5 minutes, it may or may not allow me to swipe to my home icon page... i have a large number of reminders, about 80 or so apps, my phone(s) have not been wet, I've never had a cracked screen, i have a good clean power supply (Apple has given me new chargers), some times it will snap out of it upon a phone call or maybe a calendar alert but that is a random occurrence ... I've spoken with numerous advisers or techs and most are bewildered by the history....Of course we've loaded as a new phone and I'm told that when I reload the apps from the cloud I get a fresh uncorrupted version. Is it possible to have a "bad APP" and if so how can you tell?I'm 45 miles from an apple store so it's a pain and expense to continue to deal with them. I don't want to switch to a competitor because I dread the 'cost of change' but the dread is fading pretty quickly.