Iphone won't turn on

Alright, so I have an Iphone 5s. I've had it for about a year now. No damage, no cracked screen.The problem is a black screen issue. Meaning, I can't turn it on using the sleep/wake button or the home button. I've been having this problem for about two weeks now. I have even restored it three times in attempt to fix the issue, it does not work.

I'll explain what's going on in great detail:

The iphone only blacks-out and stays that way when I leave it alone for a couple of seconds after I've pressed the sleep/wake button to turn off the display. (No apps running in the background.) I'll set it down and when I come back to check on my phone, I have a black, unresponsive phone.

And yes, I've tried the force restart and what happens is sometimes it works, sometimes it doesn't. Sometimes I have to leave my phone alone over-night to get it to turn on again.

What's weird is that when I am listening to music with my headphones in, I can press the sleep/wake button and it won't get stuck on an unresponsive, black screen.

The only solution I have come up with as of now is to leave my phone's display on forever to prevent it from sleeping. It works, but that can't be good for the battery, so I don't want to have to keep doing this.

I would like to know if this is a bug with the latest ios 11. If so, I would like to know when this issue will be fixed. And if other people are having this problem, I would like to know that I'm not alone in this.

Thank you.