Hi,
Philip, I noticed that this doesnt happen for the first time that you fly the airplane (after you install it).
After some investigations, I got a way to know if you will have that problem or not. Basically you:
1. Connect the ground power on the setup panel.
2. Turn on the battery, then the PRI GND POWER.
Now, here comes the trick. After this you will get power on the airplane, so, you turn on the beacon lights and yougo to the spot plane view and check if the beacon lights are on. If you don't see the beacon lights (the red upper and bellow-wing flash lights) on, then you will have problems on the airplane.
So, what I do in that case is to uninstall and install the airplane again. That solves the problem.
Well, this is only a desperate turn-around because I didnt find another solution and it's very bad to see that you do a very long flight and at the end you dont have approach/landing navigation aids ...
Hope that helps,