I am owner of 3DR IRIS+ which contains Pixhawk telemetery and am having trouble obtaining correct latitude. Hardware has been throughly checked and found to be in good order. Latiude is orrect when UAV NOT in line of sight of KRNO airport.
I have suspicions as to the cause, but no proof.
If your problem is regarding GPS data, let us share notes and results. In meantime, be aware of the NOTAM in the following link:
The problem I have is that you do not see anything in the FLD-02 screen. Attached some pictures to see how the port exit-2 is connected to the converter “FrSky Receiver Upgrade Lite” and that the recipient “FrSky D8R-II Plus” emitter module on the station is connected directly to the FLD-02 screen. Configuration Serial2-Protocol parameter is set to 3 (FrSky D-PORT). By going clearing doubts, the FLD-02 screen directly supports the protocol “FRSKY D-PORT” or “FRSKY S-PORT” or need a converter ?.