NRF9160 mqtt_publish stucked

[Adev]

Hello all, I have a little problem.

I`m trying to do an gateway communication using my NRF9160. The routine I`m trying to accomplish  is next :
  -- Send message over serial to nrf

  -- Recieved message send to mqtt broker ( and here is the problem ) 

After I call mqtt_publish nrf get`s stucked. As I managed to discover the problem is in : mqtt_transport_write().

To mention :

• If I send an message from mqtt broker to nrf it responds and mqtt_publish works perfectly
  
• I searched on forum and found this link that seems to be my problem as well : https://devzone.nordicsemi.com/f/nordic-q-a/49511/call-to-mqtt_publish-blocking
  • I tried nrf  v1.0.0 with nrfxlib  v1.0.0 and v1.0.0.rc4 with nrfxlib  v1.0.0.rc4 and it did not help  
• My mqtt_send_message looks like this (don`t forget that it works if first I recieve an message from broker and nrf has to respond, it is not working if I call function by myself):
  •  

    void mqtt_send_message(char *send_data)
    {
        struct mqtt_publish_param param;
        param.message.topic.qos = MQTT_QOS_1_AT_LEAST_ONCE;
        param.message.topic.topic.utf8 = CONFIG_MQTT_PUB_TOPIC;
        param.message.topic.topic.size = strlen(CONFIG_MQTT_PUB_TOPIC);
        param.message.payload.data = send_data;
        param.message.payload.len = send_data[PAYLOAD_LENGTH_OFFSET] + PAYLOAD_OFFSET;
        param.message_id = sys_rand32_get();
        param.dup_flag = 0;
        param.retain_flag = 0;
    
        mqtt_publish(&client, &param);
    }
    

Thank you very much for your help.