MAVProxy Connection Problem

Hello,

I’m making a ROV with pixhawk 2.4.8 and the companion computer “Jetson Nano 4GB”. I was connecting to my pixhawk via USB cable which is plugged into Jetson. I was using MAVProxy and QGC for ground computer to controller connection. It was going well until something I can’t understand happened.

Here’s my codeline for opening up UDP connection:
$ mavproxy.py --master=udp:169.254.242.51:14550 --out=/dev/ttyACM0,921600

When I try to connect it it says

“Link 1 OK”

but after that it doesn’t show any mission parameters (FGear_in, FGear_out) and I can see that QGC still says “Disconnected”. What should I do?

Thanks in advance.

P.S. : I’m establishing communication between ground computer and companion via PLC(Power Line Communication)