Red bar in the top of the screen

Hello guys!

About 6 months I have such a strange (and a little bit frightening, as for me) problem with my iPhones.

I have 5S and a 6. Sometimes (about 5-6 times a day that I see, but really,I think, more often) my iPhone shows me a red bar on top of the screen. That standard bar that appears, for example, when I speak on Skype in background. Red bar appears and in about 0,2 seconds disappears back, so from summer I've NEVER managed to see what's written on it.

When I listen to music and it appears, the music stops. I understand thai it happens even when my iPhone is locked ans is on charging, because I often listen to music from iPhone when I am at home, and often (aboun once on hour) the music stops. No matter from which app I am listening to it, and is it stream music or local files.

The problem is on both iPhone 5S and iPhone 6, but not on my iPad Air, which has the same iCloud account. I tried even to block access for ALL the apps to the camera, location services and a microphone, but the red bar appears anyway.

I asked my friends, but no one has even heard about this strange problem.

I do not know what to do, and even worse is that it makes me thinking that someone is spying on me.

Maybe someone has this problem too? Any ideas what it could be?