I have an issue with my 4G setup.
I am running openwrt on a TP-Link Archer C5 and on a Raspberry Pi(for backup reason).
My setup is running in germany quite well and stable.
But if I cross the border for example to denmark, the router do not establish a connection.
I have tested 2 different Sim Cards from 2 diff. Providers (O2 Max Prepaid and Telekom/Edeka).
Both Sim cards are prepaid.
Sometimes I get an Error: Unknown error (NETWORK_REGISTRATION_FAILED)
Sometimes I get an IP Address, but routing is not working
Sometimes I get no IP Address
When I plug the Sim Cards into my Smartphone, there is no issue.
Has someone ideas to narrow down that issue or where/what to look for?
Is it possible that the providers in denmark block router/non-Smartphone connections?
My LTE Modem is a ALFA Tube-U4G USB
It is used by QMI driver 1.30.8-1
OpenWrt Version 22.03.5