We’ve noticed inconsistencies in the data reported, for systems running various operating systems. Some systems aren’t providing any data related to patching—applicable, installed, or outstanding Fixlets.
Has anyone experienced this and found a resolution? Custom reports aren’t covered by standard support 
Generally that would mean that those clients are not subscribed to the related Patching sites. In the Console, are those computers subscribed to the Site, and showing Relevant for any of the fixlets?
Yes, they are subscribed and showing relevant fixlets. In other reports, they also show the relevant fixlets.
I have a case open with support and they looked at everything and said the issue is with the report and to post here.
Do the Web Reports roles your users belong to have any restrictions placed on them? IWhat happens if you run the custom report as an admin user?