My setup is RPi2B both Air and Ground, 2.02 Stretch. All works fine with RPi cam.
Then I connect XM530 IP Cam (very close to Hi3516) in H264 1280x800, 4Mbps, do all the settings for for a single IP camera in “USB/IP Cam” Wiki and get crystal clear picture (but with huge ~800 ms latency). But : no video streaming to FPV_VR (telemetry and stats still works), empty Cap and Screenshot folders on USB stick (telemetry and stats exists).
What is wrong ?