Unable to use 2nd gps only - Rtk ublox c94 - solved

Hello all.Has anybody managed to use c94 RTK as secondary GPS only ? As soon as i switch to secondary i get EK2 error.
Rover Gps has Rtk fix locked and Pixhawk shows Dgps lock, but with Gps switch to “best” i dont get satissfactory precision.I have set rate to 5hz on Rover gps so that should not be a problem. Serial speed 115200.I have set up Lora link thanks to @ktrussell’ s instruction and code and that part works well, it just seems that pixhawk is not using rtk gps properly.What parameter should i analyze to find out what is going on ?Please help

How exactly are you switching to secondary?

By setting auto switch parameter to 3 -second.0 is disable 1 is use best ( which does not work well for me) 2 is blend and 3 is use second

I am the developer that added the code for AUTO_SWITCH == 3. It works fine here.
Make sure the GPS state is “RTK fixed”

Thank you for your attention.I did that as well.I set GPS_MIN_DGPS 100.Allthough i assumed it is for feeding RTCM via pixhawk, while at my setup the rover part of rtk receives correction directly via lora.While i have a confirmed RTK fixed lock, the possition stil "floats " within meter or two which is unfortunately too much for aplication in my wineyard.I will try to record the Gps deviation, together with deviation on Fmu somehow, to compare the diference.what do you think could be the reason Ekf fails immediately upon selection of second gps? Is there any way i could tell ekf to use second gps.Or could there be any other setting that kiks in in this situation ?

Ok, i found out i have same problem as this Why skyviper can get DGPS 3D lock with it’s original EvaM8M gps chip without receiving RTCM message? It shows 3D Plus Dgpss without m8p connected.I will disable Sbas and read through entire thread.