Hello im looking for support, I recently bought the GTN 750 to update the navigation of my B727, the problem is that it doesn't fly the gps approaches even after i activate approach command on GTN, i see all tutorial on YT, for the real unit and for RXP, l and guess that should work but no, even the holding patterns not work too, is there any special configuration or setting so that the old autopilot follows the instructions of the modern GTN?