It looks like the function which produces the caps getting error sends AT+GCAP. Using screen on /dev/ttyACM0 I see:
AT+GCAP +GCAP: +CGSM,+DS,+W
OK
It looks like the function which produces the caps getting error sends AT+GCAP. Using screen on /dev/ttyACM0 I see:
AT+GCAP
+GCAP: +CGSM,+DS,+W
OK