Ai Thinker A7 MQTT

Hello,

I am trying to send a message to CloudMQTT using A7 Ai Thinker GSM/GPRS and Ai-Thinker Serial Tool.
I managed to connect to CloudMQTT (I can see the connection at Connections panel) but I can not send any message to the broker.

Flow:

AT+CGATT=1
AT+CGDCONT=1,"IP","net"
AT+CGACT=1,1
AT+CIPSTART="TCP","XXX.cloudmqtt.com",PORT
AT+CIPSEND
>

I have tried many options (with mosquitto_pub / converting into HEX) but the response is OK the there is no message in 'Received messages' panel. The broker works , I tried with cmd from the local.

Any suggestions are welcomed.