I've had this issue sporatically since I got my Mavic Pro, and with two different phones: a Nexus 6P and a Google Pixel 2XL.
About every other time I go to use the drone, the controller will not connect to the phone. The controller will show it's connected to the Mavic, but the DJI Go software will not acknowledge connection to the controller.

I have tried the following with equally sporratic success:

- Shutting everything (drone, phone, controller) off and turning back on again.
- Using a different cable to connect the controller to the phone (a USB-A to USB-C on the bottom port).
- Enabling USB debugging (a suggestion I found online).
- Unplugging and plugging back in the included USB cable.

Sometimes one or more of these will make it work. More often then not, the controller will appear to connect for a moment, showing video, and then as soon as I take off it will disconnect. Occasionally it'll get stuck in this loop where the home screen of the DJI Go app will show the "Go Fly" button, but it will disappear within a second.

Any and all help is GREATLY appreciated. It's a super great feeling to have something this expensive that I can't use reliably.

Hi we are sorry if you are having troubles with connecting your controller on your devices, kindly check as well if your firmware is updated. You may download the DJI assistant tool to check if there's an available firmware.

DJI Gamora Posted at 2018-6-12 06:17
Hi we are sorry if you are having troubles with connecting your controller on your devices, kindly check as well if your firmware is updated. You may download the DJI assistant tool to check if there's an available firmware.

Hi. I have always ensured the software is up to date on both the Mavic and my phone, however I will check over this again.

I've gone through numerous firmware updates and have had 0 change.

The problem I had on my Android device was the lock screen.  I had to remove my PIN and fingerprint lock screen and reboot.  Then it connected without any problems.

poltergeist004 Posted at 2018-6-12 08:54
The problem I had on my Android device was the lock screen.  I had to remove my PIN and fingerprint lock screen and reboot.  Then it connected without any problems.

Interesting. I'll give this a shot. Thank you!

Did that work? I'm having the exact same problem as the OP with a mavic mini.