The Simbrief ID is used to fetch the flight plan data from Simbrief (even for users without a Navigraph Ultimate subscription – albeit with possible caveats in case, for example, the AIRAC cycle does not match between what was used on Simbrief vs. what is installed in the addon).
But it cannot be used to authenticate to Navigraph for subscription-enabled features (such as third-party EFB charts access or navigation data updates), which instead use a separate, authenticated login (where the Simbrief ID/username is not needed), for example like the following in a PMDG addon:
The (second) screenshot appears to simply indicate Navigraph navigation data is not installed, rather than a lack of subscription.
jimc73 seems to be already authenticated and to have access to the navdata update (as seen on the first screenshot), it’s just failing to install for some reason.
My guess, this is most likely the following issue:
Unfortunately the workaround obviously does not work for Xbox users; I don’t think PMDG or iniBuilds have released an update with the fix yet but I am not 100% sure about that.
Regards,
Tim