I just got My iphone 7+ 32 gb two days ago from maxis, the device is working wonderfully but at times, when i open my camera, it'll bug out like it'll go blank until i close the camera app and reopen it. Another problem(rarely happens, but has happened twice or thrice), the phone will get bugged out, like when i press sleep button or home button nothing will happen until 10-20 seconds. It's like a delayed reaction. What should i do??