We are using Telenor (Sweden) as service provider. Their standard APN is "internet.telenor.se". In order to get public IP I need to use "public.telenor.se" as APN. When I add custom APN "public.telenor.se" router is still trying to connect on "internet.telenor.se". The network technician from Telenor says that he can see the router still trying to connect with wrong APN even though I saved settings and everything seems ok in Teltonika interface (RUT950). He even blocked all APN:s except "public.telenor.se" for my SIM and I changed to auto-APN setting and router was still trying to connect through "internet.telenor.se". I am not really sure what can be wrong since everything seems correct in router interface...
