Since early June with Apple
Mini 2, 16gb, WIFI tethered to my Droid hot spot, using IOS 8.4 and the DJI Pilot (whatever version it was at the time) worked perfect all summer until Sept 8 (or so) with releases of IOS 9.xx and initial release of Go. Then it went to *ell. Sitting on the lunch pad the FPV would lag and then start to black out. All fall, it was screwed up I had no fun flying and the only advice I was getting was that it was pilot error or that no one else has this problem.
I have since updated to the Mini 4 16 gb, cellular with Go 2.4.1, FW 1.4.1 with RC 1.4.3 and I select a custom channel and it again flies like a dream machine, just like it did all summer.
I don't know what corrected the problems, but I know that the combination I am now flying works great (probable 10-12 flights out to 6200') and it is
with a Mini 4.