Sorry for the slow reply
I’m in NZ too using 2degrees too, and it does work. Are you making sure to wait until you’re connected to the network and that the modem returns “Call Ready” before you start pushing commands at it?
From power up I wait for “Call Ready”, if you don’t see that at all, try AT+IPR=19200 then reboot
After I get Call Ready I pass the following commands
AT+GSV (this gives me firmware version, good way to make sure the modem is awake etc)
AT+CSQ (This reports signal quality)
The response from AT+CCLK? sometimes echos the actual AT command and sometimes doesn’t, but other than that the actual response it working very reliably (I’ve probably done 100 reboots using it without issue)