FMS Position Issue

[norcali.pilot]

Which position information do I use when initializing the GNSS/FMS?
- FMS POS puts the computer somewhere far away from where the plane physically is.
-GNSS1 / Airport is closer but the entire route up to the approach phase (including RNAV approaches, excluding LOC approaches) is slightly off course the whole time while the FMS says I'm on course. (pictures attachted)
Thank you.

NIGHT image: Established ILS 13R KHOU, PFD is centered tracking the LOC, MFD flight plan map depiction shows I am off course noticeably.
DAY image: Established RNAV 34 KRDD, PFD tracking RNAV signal and centered but aircraft is physically offset from the airport. I did a second approach using the ILS and I was aligned properly with the runway.

V1.1.19 / AIRAC 2005 / P3D V.5H2

[bkflying]

Did you ever find a solution to this problem? im having the same issue.

[Slayer]

You need to start the KA from the scenario startup screen, then in the FMS go to position init and take the GPS coordinates and copy them 2x ( unless you are departing from where you last landed)

As far as navigation data being off between Navigraph and P3D is a different issue. That is a limitation of the sim, you can probably use a 3rd party tool like in aero.sors.fr to try to get the everything to line up better...