Good day. And indeed I own this device.
The MSFS base implementation of the GNS is pretty basic. When you start the C172 steam cold and dark, and toggle avionics, there’s no startup cycle in the cockpit as well. The GNS only works as a display that shows the popped out GNS, so exactly what is happening in the sim itself. The device doesn’t have any logic in itself. Hence they call it a bezel. It’sa display with a set of buttons and dials that operate the functions. Maybe the PMS mod (that I still need to try, it’s free, adds more functionality, like a startup cycle).
Zoom on the map page works for me, in steps. When you have the device interface app open, do you see the right commands being triggered? Does the zoom button in the sim work as expected?
The functions OBS and Flight Plan catalogue I haven’t used. I always upload a plan from LNM, and use the FPL menu to invert twice to get rid of the silly MSFS waypoints.
Do these functions work directly in the sim?
Switching frequencies works for me. Do you see the commands being triggered in the device manager? Do these work in the sim itself? Do you know of any mods that could interfere?