Is there a proper sequence in booting up the device?
I used a iPad Mini 4 awhile back, can't remember anymore how since been using android till today that I decided to go back to apple.
I downloaded and installed the latest GO 4 app from apple store and now upgrading the phone IOS to 11.4.1 and will try again.
I am using the bottom USB port w/ a known good and reliable new lightning cable and nothing plugged on side of the RC.
Any tips, please let me know.....thanks.

Plug botton USB RC to iPad = OK
Try to reconnect (link) RC and drone via iPad. (DJI GO setup + press drone´s back button until you hear 2 bips)

After downloading latest IOS and installing it, it seems to fix the problem.
Will test later when the weather cool down a bit.

Hi. Thank you for the information. Please keep us posted on the result. If you have any other concerns please feel free to post it here at DJI Forum.

I've not spotted any problems with my iPhone 6s plus running 11.4.1 & V01.04.0400. In saying that I mostly use my iPad Pro 9.7, likewise though no problems seen as yet. In fact both have been very reliable over past couple of years. When using bottom port remember and unplug cable from side port, AFAIK there is only the one logical 'port' with two outlets, only one can be used at a time.