WR21 cant find carriers in Australia after firmware update

Hi,
Using firmware V5223 and tried various newer firmware up to the latest V52145 but when rebooted the modem cant find any Australian carriers such as Telstra using the original working SIM.
Also the SIM info says no IMSI after reboot.

The API settings are the same (Telstra.iph or Telstra.extranet). Tried rescanning network but no luck.

Any ideas?

Thanks to Praveen Paul from Kapp Engineering for the successful resolution.

The Cell module turned itself off during the firmware upgrade!
To turn it back on:
Telnet into the device and runt he following CLI commands:
muxon
config 0 save
reboot

The Cell module instantly turned on and started scanning the mobile network and then logged onto the network.