Pressed buton time PROBLEM!

Hi. I want to add machine gun to my mobile game. The system I want to do is simple. Hold the button and shoot. Release the button and stop the shoot. I need two events for this.
1. Pressed button.
2. Released button.

When I hold down the button, it is released on average after 0.80 seconds. But after holding it, if I move it a little bit, I have the right to hold it as long as I want. This is really weird.

How can I solve it? I just want to make a machine gun for mobile. (I’ve made a pistol who works with clicked button and it has really worked.)
Video: 20201010 191213 - YouTube