So I've been experiencing today that when ever I tap on my screen to go to another letter or use the text highlight to 'copy' a text, the screen goes black. Until I start typing or hit the space on my keyboard on my phone, which is making typing, going back, correcting errors, etc., so difficult. 
Sorry I might not be able to respond to your replies much, though I'll be reading them. If it's maybe something on my side, then I'll see what I can do to help fix it.