NB-IoT attach issue

[sauron]

Hello,

I'm trying to attach to NB-IoT network and the outcome is:

lte.attach()    <-- i can see on S1 interface that there are no messages
lte.connect()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OSError: modem not attached

The outcome of CEER:

>>> lte.send_at_cmd('AT+CEER')
'\r\n+CEER: lastEmmCause: NO CAUSE RECEIVED, lastEsmCause: NO CAUSE RECEIVED\r\n\r\nOK\r\n'
>>>

I have: Pytrack board + Gpy board with NB-IoT software:

lte.send_at_cmd('ATI')
'\r\nSEQUANS Communications\r\nVZM20Q\r\nUE6.0.0.0\r\n\r\nOK\r\n'
 lte.send_at_cmd('ATI1')
'\r\nUE6.0.0.0\r\nLR6.0.0.0-37781\r\n\r\nOK\r\n'

anybody seen this ? What can i do ?:) Sim card is inserted and AT+CIMI returns proper IMSI. Is there any generic "howto" or guide how to attach to IoT network?

also after some time the response for every ATI command is:

>>> lte.send_at_cmd('ATI1')
''
>>>

also hello ;) my first post here

br,
Tomasz