Just for the record, we are working with Steve at FlightBox on this now. I'm seeing the same thing. The Pi2 with Edimax is not sharing, but the Pi-3 is. Trying to see if a prior build was working. I don't have another WiFi dongle to test right not, but will shortly.
We are also going to look at the WiFi config to see if there is a patch or update that might fix this.. It simply could be a hardware issue with a particular Edimax dongle. We will know more shortly. New devices with the Pi-3 will not have this issue.
Flight Plan sharing is working on other devices like Clarity, iLevil, SkyRadar, SkyGuardTWX, etc, but there seems to be an issue with the Edimax dongle. Stay tuned.