I'm having issues setting up a wired connection with Mavic Air to its controller. I get to the 3rd step in the process and the DJI GO 4 app doesn't recognize the connection between my phone and the controller and doesn't allow me to proceed. I've watched tutorials and followed instructions step-by-step and cannot figure this out.
Things to note:

• Using iPhone SE.
• Not a faulty cable because my phone is charging when plugged into controller.
• I've updated firmware for both Mavic Air and controller through DJI Assistant 2.
• Light on controller is green.
• Light on Mavic Air green light that periodically blinks twice.
• I'm able to connect via WiFi when choosing that method.
  

Have I missed anything or is there something wrong with my Mavic Air?

Is your DJI Go 4 App updated to latest version?

Is the micro usb end of the cable firmly plugged into the RC?

Is the lightning adapter end firmly plugged into the phone’s lightning port?

Did you turn on RC?

I've had this problem. What I do is with everything on, unplug the RC cable at the remote and plug it back in.

I get the same thing if I try and connect to my iPad, but my iPhone works just fine.

@Hummingbird.UAV - Thanks this worked! It took a couple tries but unplugging the cable from the RC end and plugging it back in got it to finally work.

Hummingbird.UAV Posted at 2018-2-4 05:47
I've had this problem. What I do is with everything on, unplug the RC cable at the remote and plug it back in.

This is all you need to do usually. With my Ipad I just pull out the lightning cable and plug it back in again and away we go

So the same thing happens to me.  I have tried my Zenfone V (or 6 or whatever) a galaxy note 4.  A Zenpad S (something), this one actually worked and now when i woke up this morning it no longer connects to the controller,  Does the same thing as the other devices.  Tried my girlfriends super low end LG phone and it worked pretty flawlessly, it let me fly a couple of times but have not tried it since.

Im starting to think my controller is defective

Not sure why it posted twice...

My first post was an official disaster. What I meant to say was...

Same thing here with my iPad mini 3 and the usb connection on the bottom of the remote. Same issue with multiple cables. IPhone X works fine with side connection.

After unplugging and replugging at the remote it eventually works.

Anyone know why this is happening.

I am having the same problem worked fine in Hawaii not so much in vietnam. Need help

Power and data are different pins on the cable .. try a different cable

SAME PROBLEM but!
I am using Samsung Galaxy S8+ and started to have the same problem with connecting to the controller. Even connecting through Wi-Fi is a problem.
I figured out that if I connect my controller with a standard USB-B (the big one on the bottom of the controller), then it is working just fine. Only the short small cable leading to the side of the controller is making the problem. Same as the TOP one, the phone is charging, but not connected to the remote. I did try the solutions above but they did not work for me. Does anybody have a better solution than using the big cable???