Dual GPS redundancy

in my drone whit Pixhawk 4 i installed a GPS RTK as primary gps and the standard holybro GPS as secundary gps.
I modified parameter EKF2_GPS_MASK to 2 and seem ok but if i detach primary RTK GPS when drone is started the secondary GPS standard does not enter into operation and the drone remains without any GPS neither the primary (which is deliberately disconnected) nor the secondary that should go into action …
Did I do something wrong?

Thank’s to all


Did you detach the primary before booting? The secondary waits until the primary has data in order to ensure it is the secondary publisher. At the same time this ensures that you don’t takeoff with only the secondary GPS without realizing that the primary is not working.

Ho @bkueng bkueng thank’s for your reply
i detach primari RTK GPS after booting…

After it’s already recognized?
Can you provide the output of gps status?