FiPY NB-IOT connection never attaches Vodaphone Sim London

[lbdl]

Hi All,

I attended the London event back in July and have just been trying to connect to PyBytes using the Vodaphone sim supplied back then with no luck.

I've followed the example quoted in this post https://forum.pycom.io/topic/5030/using-pybytes-with-fipy-nb-iot-and-vodafone-sim-from-goinvent-london-event/2

But I cannot get the modem to attach to any network, this may because there is no network to attach too. Can anyone shed any light here or point me in a direction to investigate as to if perhaps I need to reflash the modem to be CAT-NB1 the docs are somewhat unclear

output of os.uname() below:
(sysname='FiPy', nodename='FiPy', release='1.18.2.r6', version='v1.8.6-849-a210e85 on 2019-05-13', machine='FiPy with ESP32', lorawan='1.0.2', sigfox='1.0.1', pybytes='0.9.12')

I suspect that perhaps I am getting no signal at all though as indicated by:
send_at_command('AT+CSQ')
returns
CSQ: 99,99

which if I am reading the command sheet right means not known or detectable.

I'm lost here as to what to trouble shoot, the chipset, the antennae etc...