Pixhawk Cube (Black) + DJI FPV air unit OSD

I have two DJI FPV air units mounted on a two wing. One with Matek F405 and the other with Pixhawk Cube.
Parameters and wiring are exactly the same, except for Cube where I am supplying a separate voltage to power the DJI air unit since the air unit requires 7+ volts and the Telemetry port can only supply 5V.
I cannot get the OSD to display on the Pixhawk Cube!!!