It just can't hold the antenna in one place. You can move it with just two fingers. Anyone observed it?
Is build plastic over plastic, it has no chance to stick in one place. Maybe if you glue it after aiming is over.
Yep they are basically rubbish.I've had problems with quickMOUNT pro (standard version). I get them with mANT 15 devices and they are always easily movable even after being VERY strongly tightened. They are basically the same mount only differing in endings that connect to the antennas.