This started happening on my iPhone 6 about a month ago. Never happened before.
For me, it started out of the blue and is random. I could take my phone into an Apple store, but there's no telling when this screen blackout will happen.
When it does, I have to hard-reboot the phone to even get it to hang up. Taking the clear plastic case off doesn't help (same case it's had since I got it). No screen protector or anything else on it. Then, every single time, I have to resort to placing the call again on Skype.
This seems to only happen when I'm on a call that has a computerized 'tree' I have to push numbers to work through (i.e. "press 1 if you know the employee's name, press 2 if you know the employee's department," etc etc).
I see these very long threads about this problem here on Apple's site, but I don't see any solutions or explanations. This makes my iPhone completely un-usable for many calls. NOT the point of having a smartphone.
My stab-in-the-dark guess is that maybe it has something to do with an IOS upgrade they did at some point? I've had my phone for more than 2 years and never had this problem before. Now, all the time.
Anyone have any constructive, useful information about this? Apple staff, please?