when i connect other devices to my hotspot, the wifi connection established but the connection to the internet don't.
I do the same in my nexus 4 and everything works properly
I also have a light glow if I set the brightness to minimum and set a black background and look at it in a dark room. It's perfectly black if I set the brightness to max. But you can only see it in a dark room.
I just checked it now and it works properly. Anyway do you have a working mobile data connection on your Z1 Pro? Try to ''forget'' the hotspot connection on your other device, then turn off and on its Wi-Fi, and connect to your hotspot again.
Thank you, I just wanted to make it clear that when the brightness is up or its bright around me the black is black. It's only when the screen is lowest brightness and the surroundings are almost pitch Black I notice it. But thanks again.