What's wrong with this canvas code? Help Me PlEaSe

Question

I wrote a simple code for dragging squares around the canvas:

https://code.sololearn.com/WdtdAHJCBEav/?ref=app

It works, I can drag squares, but there are very frequent misstouches.
I mean, when i check the coordinates of user touch in "touchstart" for matching square coordinates, the condition returns false, even if the touch matches square .

Please help

Answer 1

Edited lines :-
line 53: -30
line 54: -30
line 55: -30
line 56: -30
line 63: if(e.cancelable) e.preventDefault();
line 73: if(e.cancelable) e.preventDefault();

https://code.sololearn.com/WZJC9mKmTngq/?ref=app