Cat-M sim card cannot attach in Australia

I am using Pycom with Hologram sim card in Australia. These days it seems to be so unstable and cannot attach to the network. I have done the connectivity troubleshoot. The result is
>>> lte.send_at_cmd(‘ATI’)
>>> lte.send_at_cmd(‘AT+CGMI’)
>>> lte.send_at_cmd(‘AT+CGMM’)
>>> lte.send_at_cmd(‘AT+GMM’)
>>> lte.send_at_cmd(‘AT+CPIN?’)
>>> lte.send_at_cmd(‘AT+CCID’)
>>> lte.send_at_cmd(‘AT+CFUN?’)
‘\r\n+CFUN: 0\r\n\r\nOK\r\n’
>>> lte.send_at_cmd(‘AT+CFUN=1’)

In the board, I config:
AT!=“RRC::addscanfreq band=28 dl-earfcn=9410”

I am pretty sure that I am using the same config and it can connect to the network before. But now it cannot connect any more.

The AT+CPIN? returns ERROR and AT+CCID also returns ERROR this likely means the device cannot read the simcard, make sure you have the simcard installed correctly. This is why you cannot connect.