Yes with screen protector but it's not SP issue. The LCD is like showing a bit darker or shadow on the area I highlighted. The darker spot look so obvious when display on white background.

Looking at your case, it seems to be the screen problem already and not the tempered glass. You can try all types of tempered glass brands and you will most probably experience the same problem.

This happens because most probably the sides of your glass screen is "more curved" compared to the "normal glass screen curve", hence screen protectors cant stick at the sides.