BG770A-GL looses connection with carrier

Hello,

we have the problem, that the modem looses connection to the carrier after 30minutes - 1 hour. Our network provider told us that the modem did not respond to the paging requests and got kicked out.
When we connect to another network provider this works like a charm.
Is there anything I need to configure differently?

Modem Version: BG770AGLAAR01A05_01.200.01.200

Hello,

Is there anybody who might help me?
Maybe for some clarification:
We use the BG770A in Austria and it works as expected if connected with network provider A. If we are connected with network provider B we loose connection quite often.
In Slovenia is only network provider B.
Network Provider B told us the modem does not respond to paging requests.
How can this happen?