Having browsed the forum. It seems that the 2017-08-21 released firmware in combination with DJI Go 4 4.1.10 and .11 caused
1) Shorter flying range when connected via wifi
2) range limited when using OTG
3) unable to unlock nfz

Anything else?

4) Video lag

Yes bit they fix the mid air fall problem....

I think the DJI GO 4 app updates (especially .11) are in readiness for firmware update .700 which a lot of people are speculating to be released this Thurs 28 Sept. The home point will update itself every 20 seconds when the pilot is using gesture controls so if it runs low on battery it will return (presumably not too far) to the last designated home point and not right back to where it first launched - which makes sense. The home point is also recorded on the map as a large orange 'H' rather than a small green one. There is also speculation that a new gesture mode may be introduced too including a paper plane mode for the Spark whereby it will takeoff in forward flight from the hand but this is yet to be confirmed. Range when using the OTG on IOS is definitely limited to Hz.100m and Vt.50m but the WiFi connection seems to have massively improved both lag and range in my experience after manually switching to 2.4GHz with no preset limitations. I think the IOS11 update has something to do with it too. I also find that you can now only tilt the gimbal up +30degrees in tripod mode and the manual adjustments for the gimbal have been put together for pitch and tilt options in the same setting.

I use .11, but no range limitations with OTG. Still pop-up Unsupported.