Hey, I was in several foreign contries for the past few weeks, but I'm back in my home country now.
I had some issues with connecting to other networks on roaming while in roaming. I was using "auto APN" all the time. My provider at home is vodafone and it was always no problem to connect to vodafone in other countries. But if vodafone wasn't available or connection poor I tried to connect to other network operators, but it always failed either with "timeout" or with "access denied" (or something similar). And it also never used another provider on its own, I just had "no network" if vodafone wasn't available.
Another issue was that it often took several hours after crossing the border till it worked in the new countrys network. Sometimes I had to manually reboot the modem. I thought that it should work more easily after not more then some minutes.
The last question is how to set it up correctly, so it only uses SIM2 for roaming and automatically switch back to SIM1 when this one is no longer in roaming. I set it up the following:
SIM1 to SIM2 - on roaming
SIM2 to SIM1 - switch back to primary SIM card after timeout (but I wasn't really sure if the timeout is minutes?)
and if it would then try to always switch back to SIM1, lose connection and this every several minutes? or would it check in background if SIM1 is still "on roaming" an therefore keep SIM2 connected the whole time? Or is there a completely different way to set this up correctly.
Thanks for any help and don't hesitate to ask me, if you need additional information and I'll try to provide everything necessary.