If that. Controller will only put out 500mA, and a phone can easily use more current than that, the excess drawn from the phone battery. The Go/Fly apps draw lots of resources.When you say it’s “not charging”, are you expecting the phone power level to INCREASE while flying your drone? Because it will not.
My controller will provide JUST ENOUGH power to my phone to keep my phone power level CONSTANT while flying my drone. Whereas if the controller is not charging my phone, the phone power level will DECREASE by about 1% for every minute I fly my drone.