Cant establish connection MQTT - BC66-NA

Hi! Im using a qectel bc66-NA chip and I have tried several times to follow the example in the datasheet (BC66&BC66-NA MQTT Application Note) to connect the devices to AWS, but it never worked. I couldn’t go beyond the command “AT+QMTOPEN=3,“a3pupxb4was62j-ats.iot.us-east-2.amazonaws.com”,8883” because the module’s response indicates that it failed.

We suspect that the issue may lie in the device’s acceptance of the certificates since the module’s response is ALWAYS “+QSSLCFG: 1,5,“cacert”,0”, even though we have tried with several certificates. Is there any possibility that the module only accepts certificates up to a certain number of characters?

Furthermore, I have already tried connecting to AWS using the MQTT fx tool application, and it worked correctly, eliminating the possibility of the issue being on the AWS side.

Can you send your command flow and let’s see what the problem is?

Of course!!

But now im with a new problem. I cant connect with MQTT server because i receive all the time a Error message.

Visualization window
AT+QSCLK=0
OK

AT+QSSLCFG=1,5,“seclevel”,2
OK

AT+QSSLCFG=1,5,“cacert”

+QSSLCFG: 1,5,“cacert”,1187
OK

AT+QSSLCFG=1,5,“clientcert”

+QSSLCFG: 1,5,“clientcert”,1223
OK

AT+QSSLCFG=1,5,“clientkey”

+QSSLCFG: 1,5,“clientkey”,1675
OK

AT+QSCLK=1
OK

AT+QMTCFG=“ssl”,3,1,1,5
OK

AT+QMTCFG=“version”,3,4
OK

AT+QMTOPEN=3,“a37v7766duc57r-ats.iot.eu-north-1.amazonaws.com”,8883
OK

AT+QMTCONN=3,“clientExample”
ERROR

Im not receiving any confirmation by QMTOPEN… but if when i didnt sent correctly some certificate, i received +QMTOPEN: 3,-1.

Need some help.
Regards