Telemetry to ground station via mavlink on a F405 Wing

Hi all, I am struggling to get a connection and telemetry to my ground station & taranis.

I am running RFD900x for RX and Telemetry on the plane and TXMOD in the taranis for TX connected to the F405 Wing via the smart port single wire and control is great. I have tried UART1 and UART2 for telemetry connected to the RX/TX pins of the RFD900 with the serial protocol as 1 (MAVLINK1) and the options as 0,4 and 7 with no result.

The same configuration works on my copter but that uses a pixhawk FC so I suspect it is something to do with how the F405 is reporting the telemetry.

any ideas on what is wrong ?.

Somehow it worked retrying the same settings I have already tried… so who knows, maybe Mavlink2 instead of Mavlink1 was the key after a typo on the original settings.