It looks like something is wrong with the serial connection from the Arduino to the PC. Serial Monitor is not receiving all of the characters the Arduino is sending. What you are SUPPOSED to see is something like:
Sketch started.
ATCommandStream started at baud rate nnnn
Sending command: "AT"
Received: "OK"
Sending command: "AT+CMEE"
Received: "OK"
Sending command: "AT+CSQ"
Received: "+CSQ=27"
Received: "OK"
The fact that some of the characters sent by the sketch are not showing up in Serial Monitor means that there is probably something wrong in the connection from the Arduino to the PC.