BG96 connect MQTT : Fail to parse domain name

I am working with bg96 communicating with MQTT. When I use GSM network to connect to MQTT it works fine. But when switching to NBIOT network, it leads to “Fail to parse domain name” error. Has anyone encountered this error? Below is my program.

AT+COPS=0,0,“Viettel”,9

OK

AT+QICSGP=1,1,“nbiot”,"","",1

OK

AT+QIACT=1

OK

AT+COPS?

+COPS: 0,0,“Viettel Viettel”,9

OK

AT+QMTOPEN=0,“http://tailor.cloudmqtt.com”,12269

+QMTOPEN: 0,4

Mqtt is application protocol , it is not related with GSM or nBiot , so this fault caused by low network rate and network overhead .

for example ,do not connect AWS from china mainland via NBiot

Hi @Stephen.Li-Q and @QuangPhuoc

Are you able to resolve above issue ? I facing exact same issue while connecting to iot hub via MQTT in EG25 module

Make sure you do not have http:// or something similar in the host_name.

I have the same problem with my BG96, I can use MQTT with LTE-M but when I switch with NB-IoT I can not use MQTT. In fact, the problem is that the the low native speed of NB-IoT does not allow TCP/IP in many situations.