Windows sensors going off but they are not open.

Ever since my security system was installed, windows sensors go off randomly. The windows are never opened when this happens. This does not happen everyday, but it does happen from time to time.
We have 7 window sensors and it’s not always the same location.

 

A security technician checked the sensors and notice they were placed too close. But, today again, another sensors went off and the windows was closed.

 

What could be the problem? I have called multiple times for this, but no one can fix this issue.

I am worried that one day the alarm will go off because of these sensors.