There was some discussion about this recently and the general consensus is that the way you have yours mounted is wrong.
Please see diagrams in this thread
I’d love to see what results you get if you do reposition the antennas as per the diagrams.
As an aside, I don’t know which country you are in or what regulations are like there but flying experimental control systems over a built up area (even if it’s just a bixler) doesn’t seem all that responsible to me.