So can we say that the issue is
“2.6.3-u-(t?)-xxx-official-(FP4?) update prevents use of Murena (and other ?) eSIM”
Is the problem limited to Fairphone 4 @ccgauvin94, @Melinoe @masonhh – or other ?
Is the problem limited to the official build of Android 14 (U) ?
It is always a problem with “I have exactly the same error” 
please could you define the above by just adding you build_version_string as [HOWTO] Give complete /e/OS version info easily for support, answers, comparison etc.
Does the issue only affect eSIM ? Only @Melinoe mentions Murena Mobile, please could you mention other carrier services impacted ?
… or can the problem be reported more exactly ?