Good day. Thank you for your question.
It appears that there may be some platform/server integration issue here, which is why there is no response from the device. However, you mentioned that you are receiving an error when you try to enable "send SMS" from your platform/server, so may I know if your platform/server is able to send GPRS commands? If yes then you may go through our protocol for device-server communication over GPRS messages - https://wiki.teltonika-gps.com/view/Codec#Codec_for_communication_over_GPRS_messages
Also, as you have advised above that the device responded when you sent the command via SMS but not when sent via Traccar. Just to clarify on the server settings, if you have sent the correct command. To change the server settings, the SMS commands are as follows:
With username and password : <username><space><password><space>setparam 2004:your domain;2005:your port;2006:0
Without username and password : <space><space>setparam 2004:your domain;2005:your port;2006:0
Kindly take note that if you are sending it via GPRS then there is no need for username, password or <space>
You may refer here for the list of SMS/GPRS commands - https://wiki.teltonika-gps.com/view/FMB_SMS/GPRS_Commands
You may refer here for the Parameter List - https://wiki.teltonika-gps.com/view/Template:FMB_Device_Family_Parameter_list
Kindly go through this and let me know if it helps.