Failed to publish to a topic in AWS

I'm using DA 16200mod evk  to publish to a topic in Aws. Downloaded the DA16200 firmware image '.ttl'  script from DA16200_DA16600_AWS_v3.2.8.0_ATCMD_img. Have sent the three certificates files over uart.I have done the configurations using AT commands sending from nRF52840 DK uart, as follows

"AT+AWS=SET APP_THINGNAME tap-pet-nrf-device\r\n");
   
("AT+AWS=SET AWS_BROKER a3kbzziaf9hg4n-ats.iot.us-east-1.amazonaws.com\r\n");
    ("AT+AWS=SET APP_LPORT 8443\r\n");
    ("AT+AWS=CFG 0 sample/pet 0 0\r\n");
    ("AT+AWS=CMD MCU_DATA 0 sample/pet 25\n\r");
All in station mode
As per the manual after this a factory reset is to be done which leads to soft ap mode and waiting for provisioning. But here it is entering soft AP mode but no wfscan happens or provisioning cannot be done. 
In teraterm I'm getting it with error as shown below (when nrf transmits AT COMMANDS to DA)