Thank You for making this clear,
So i still have a Walkera 2.4Ghz air & ground unit lying around .It worked with the Pixhawk i tested it a while ago.
This would be a better option for this you think ? .
Oh what…ill plug it in !..and see… 
EDIT-1 04-09-2020 …tested it on 2,4Ghz, Air to Ground Telemetry same result… 
(just to make it clear …The walkera Ground connects Through BT with PC or Android device and with 2.4Ghz to the air unit on the Pixhawk )
EDIT-2 05-09-2020 Non of the Air-> Ground units work. The Luna’s block all traffic when connected .???
Followup;