Debug mode of example/GSMScanNetworks not working

Hardware Arduino GSM Shield
1

Just wondering anyone encounter this problem. I've set debug mode for the example/GSMScanNetworks:

GSM gsmAccess(true);

However, I don't see the AT commands between the Serial Monitor and GSM shield being displayed. Any suggestions? Thanks.

2

Have you activated Serial.begin()?

3

Yes, it is activated using the Serial Monitor. Messages are being display, but without the AT message between Shield and Uno.

4

Without debug mode, does GSMScanNetworks works properly?