I think it's the app version in combination with whether you are connecting via OTG or not. I did some experiments, I have two app versions, the red icon one from here that I use for flying all the time, and an older blue icon one that I think was the original "put it in fcc mode hack" 4.1.3 is the version according to the about dialogue, so...
Connecting directly to the spark via wifi on 2.4:
4.1.3 Blue Icon - works fine, reports rssi fine.
4.1.15 Red Icon - as OP, works fine but no rssi reported.
Connecting to spark via remote, with OTG cable on 5.8g, didn't try 2.4:
4.1.3 Blue Icon - works fine but no rssi reported
4.1.15 Red Icon - works fine but no rssi reported
Connecting to spark via remote, via wifi (phone to remote 2.4, remote to spark 5.8):
4.1.3 Blue Icon - works fine, reports rssi fine.
4.1.15 Red Icon - works fine, but no rssi reported.
When I say works fine, I mean the craft flies ok.
So for me, it's a case of there is something in the app that is either preventing the data being reported, or shown, another thing I've noticed is randomly within the app some icons won't show, the one that happens most is sphere mode in photo mode, but if I tap on where the icon should be, it switches into that mode no problem, maybe this is related?
Another thing I've noticed is that until a home point is set, the red arrow on my map is always somewhere in the middle of Kazakhstan, I assume the red arrow is where the aircraft thinks it is, might this explain fly always when people take off without setting a home point? Poor little Sparky thinks his home point is Kazakhstan so when he looses connection, he looses his shyte and bounds off in an eastern direction never to be seen again because home point is Kazakhstan, not where you are standing?
I do not use any official release app from DJI, so if someone wants to repeat these tests with one, feel free, we can compare note.
But imho, it's a bug in the app and nothing to worry about.
