RC Lost, pixhawk 4 mini, qgroundcontrol

Dear people.

I do have:

    pixhawk 4 mini.
    Jetson TX2
    Ubuntu 16.04 installed
    Qground version v3.5.6
    PX4 firmware 1.9.2 instaalled on QGCS

On the SDcard side under the /etc/extras.txt

mavlink  stop-all
mavlink  start  -d /dev/ttyS1 -b 921600 -r 200 -m onboard
mavlink  stream -d /dev/ttyS1 -s ATTITUDE -r 200
mavlink stream -d /dev/ttyS1 -s HIGHRES_IMU -r 300
mavlink stream -d /dev/ttyS1 -s ATTITUDE_QUATERNION -r 200

The mavors launch looks like this:

<arg name="fcu_url" default="/dev/ttyTHS1:921600"/>
<arg name="host_ip" default="host_IP" />

    <include file="$(find mavros)/launch/node.launch">
    <arg name="pluginlists_yaml" value="$(find mavros)/launch/px4_pluginlists.yaml" />
    <arg name="config_yaml" value="$(find mavros)/launch/px4_config.yaml" />
    <arg name="fcu_url" value="$(arg fcu_url)" />
    <arg name="gcs_url"       default="udp://@$(arg host_ip)" />
    <arg name="tgt_system" value="$(arg tgt_system)" />
    <arg name="tgt_component" value="$(arg tgt_component)" />

When I run the mavros launch file I get a message in QGCS

RC control lost
Data link lost

And sometimes both

And, then the return mode failsafe action is activate it, and the drone returns. In this time, the drone does not respond to the RC commands even the position flight mode is active.

I made a RC control test with the drone without propellers and moving the RC control closer and far away from the drone. I can see in the .log file a RC quality control 1-0 output. I do not know how to interpret it.


How can I solve this problem?