Issues with GTN 750/650 NAV2 integration in X-Plan

[fritz.vogel]

I am currently running a simulator based on X-Plane 12 and using the TDS GTN 750Xi and GTN 650Xi plugin together with RealSimGear hardware for the GTN 750, GTN 650, G500, and G5.
In my setup, the GTN 750 is configured as NAV1/COM1 (Pilot side) and the GTN 650 as NAV2/COM2 (Copilot side), with crossfill enabled. The G500 and G5 displays are used to show the NAV sources.

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Problem description
When flying approaches, I encounter the following issues:

1. ILS approaches via GTN650/NAV2
   • G500 on NAV2: LOC + GS correct (green).
     
   • G5 on NAV2: GS appears and is valid, but the lateral needle is magenta (GPS-like) and points to the wrong direction.
     
2. VOR approaches via GTN650/NAV2
   • G500 on NAV2: correct behavior.
     
   • G5 on NAV2: magenta GPS-like needle and a frozen glideslope indication (which should not exist for a VOR).
     
3. LPV approaches
   • Via GTN750/NAV1: glidepath sometimes does not appear or is inconsistent.
     
   • Via GTN650/NAV2: before UNSUSPEND, the GS is shown but frozen; after UNSUSPEND it becomes correct, and both G500 and G5 show proper indications.
     
4. General observation
   • The G500 behaves correctly on NAV1 and NAV2.
     
   • The G5 shows wrong colors (magenta instead of green) and “GPS-like” indications on NAV2 sources.
     

I also tested with the RealityXP GTN plugin: in that case, almost everything works as expected, except for VOR on NAV2, where the G5 also shows a magenta GPS-like needle with a frozen GS. This makes me think the issue could be related to how NAV2 outputs are mapped.

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Current settings

• GTN750Xi: NAV1/COM1, GPS1/VLOC1, “Connect GPS to HSI” enabled
  
• GTN650Xi: NAV2/COM2, GPS2/VLOC2
  
• Crossfill enabled
  
• Legacy VC Integration: tested on and off, same behavior
  
• “Connect GPS to VOR”: disabled
  
• “Connect GPS to Autopilot”: enabled
  
• “HSI Auto-Slew”: enabled
  

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Question
Could you please confirm if my settings are correct for this kind of dual GTN750/650 + G500 + G5 setup?
And is the described NAV2/G5 behavior a known limitation, or are there adjustments I can make to the configuration files to solve this?
Thank you very much for your help,
Best regards