FrSky Neuron ESC SPort Telemetry and Pixhawk4 issue

Hi All,

I am trying to get esc telemetry to MP but without success. The esc is FrSky Neuron 60 (which supports BLHeli32 and I successfully use Dshot300 to drive the esc). I have the Pixhawk4 autopilot board with ArduPlane V4.3.5 firmware and I tried to use telem2 as the serial port to get esc telemetry (voltage, current, etc) but without success so far. Neuron esc has Smart port (SPort) which I have enabled through BLHeliSuite32 (i.e. Auto Telemetry set to on). Also updated the esc firmware to the latest 32.9 version.

So I set SERIAL2_PROTOCOL=16 (Pixhawk4, UART 3), SERIAL2_BAUD = 115 and I connect with a single wire the esc Sport to the serial port Rx pin. However I cannot receive any esc telemetry data on MP. I have also tried SERIAL2_OPTIONS=0 and 1,4,5 without success. I do reboot every time I change the serial2 settings

(I have set serial0_protocol=2 and serial1_protocol=2 and I use a usb cable to connect with the PC)

I have searched the net and I am confused a bit, if I have to use external diode and/or pull-up resistor and/or change any of the serial2_options? What I am doing wrong? I would be grateful for any help and suggestion to try out!