I bought 2 dji osmo mobile. 1 for my sis and 1 for myself. But I am unable to balance an iphone 7 properly even with the 2 knobs. It will only balance properly if i slide it away from the rubber base. But I found that tit will vibrate alot and the gimble motor to become very hot. My sis has no problem with her dji osmo mobile. Did i get a dead on arrival product?