Problem solved 🤩
On the provider side all was fine, sim active without any problem but still no connection on the CI. 🥴
While my provider was trying to find a solution for the problem I started ‘investigating’ a bit myself and found that APN settings were not present. Found a website (apnsettings.org) that lists these settings for a bunch of providers and entered an APN profile on the CI (with obviously APN settings required for my provider) and that did the trick.
CI is now online with the sim 🤩