PixRacer FrSky telemtry sensor lost (SOLVED)

I am trying to set up a new PixRacer and send telemetry to my Taranis X9D Plus radio via the Smart Port. I wired the S.Port into both the serial 4 Tx and Rx. In Mission Planner I set Serial Protocol to 4, and the baud rate defaults to 57600.

When I power up the board, it sends data for just a few seconds and stops sending. The only streams that keep sending are Rx battery, RSSI, and A2.

Does anyone have any ideas?

I now have telemetry!

In case anyone ever searches for this, here is the solution: update the XSR firware. There are many YouTube videos on how it is done.

I also try to connect my Pixhawk to an R-XSR.
I thought you need a RS232 to TTL converter and connect it to the Serial 2.
My RS232 TTL converter gets hot within seconds. I think I fried one already. The second one I disconnected after feeling its getting hot again.
I wired it that way:

Except for the red and brown to the receiver. I connected just the yellow one as the power and gnd are connected to the receiver already.