NB 1500 in the UK

I am in an area whether there is Vodafone NBIoT Service in the UK, and have a SIM.

I am trying to get the test programs working. I can get the Test Modem script working fine and I get the IMEI back (https://www.arduino.cc/en/Tutorial/MKRNBToolsTestModem)

Now I trying the Test GPRS script here https://www.arduino.cc/en/Tutorial/MKRNBToolsTestGPRS and I hit problems.

I have combined the two scripts, actually, to try to debug .. I see this on the serial debug ..

Starting modem test...modem.begin() succeeded
08:30:16.346 -> Checking IMEI...Modem's IMEI: 352753090818780
08:30:16.381 -> Resetting modem...Modem is functoning properly
08:30:16.484 -> Connecting NB IoT / LTE Cat M1 network...Test point 001
08:30:16.484 -> nbAccess.begin=

And there it hangs, the problem being that nbAccess.begin never actually returns! There is no PIN set on the SIM.

The bit of code is ..

// start module
// if your SIM has PIN, pass it as a parameter of begin() in quotes
  Serial.print("Connecting NB IoT / LTE Cat M1 network...");
// if (nbAccess.begin(PINNUMBER) != NB_READY) {
  Serial.println("Test point 001");
    if (nbAccess.begin("") != NB_READY) {
    while (true);

Anyone have any ideas? Poor that the library function never returns!!