Samsung Galaxy S5 dialing annoyance

When I call someone, after touching the green dial button I usually lift the phone to my ear immediately. But recently I become faster than my Samsung Galaxy S5. If I lifted the phone too fast the screen wouldn’t turn off at all, I had to move the phone away from my ear and put it back again to have the screen turned off.

Turns out, this is not a direct bug just a byproduct of a feature. I have turned on a Display feature that keeps the screen on until I look at the phone (under Display -> Smart Stay).

Turning off Smart Stay solved the problem, looks like Samsung needs to polish its software further.

EDIT:

Nope, it did not solved the problem, it is happening all the time.