When doing automatic network selection, modem is disconnected

When doing automatic network selection, modem is disconnected.
This was seen on a device, where a multi provider SIM is used. The modem is an RC7620.
When the modem selects Vodafone, an E-UTRAN network (AcT code is 7), the connection is lost in a couple of minutes after it was established. I am not sure if this Vodafone specific, or for all E-UTRAN networks in roaming mode.
But when we select the same network manually, the modem works fine and the connection stays alive.

not sure if this related to “SINGLEAPNSWITCH” in AT!CUSTOM…
can you check “AT!CUSTOM?”