By YAN-YU DAI 1368745
#527626 As the title
I'm using P3d v4 now.
When I turn the transponder switch to the far right in PMDG 777 cockpit, vpilot's mode C can't be activated, so after turning the switch in the cockpit, I need to activate mode C in vpilot window or in P3d's menu bar.

I didn't have this issue with Aerosoft Airbus Professional P3dv4. It can automatically change xpdr mode.

I have reinstalled all the simconnect installers in p3dv4\redist and also reinstalled FSUIPC. I don't know whether it can help but the same issue still happened.

Is there any way to solve this issue?Thanks