In the Capture2.PNG is it just me or do you not have the checkboxes selected for the tag?
Another option is to build a gallery of cards based on the category or the group.
It almost seem as though the tags are only search the main group of data that is created when the GeoHub is built and not any of the attached data groups that I need the cards to search. When just generally looking at the data it all shows but the tag search does not work.
It seems to be anything in this one group can't have the data searched. All of the data shows when I view the Content Manager but when viewing the live site it does not show. The group is open data and I have even tried to just add each item individually to the content library instead of that group and for some reason the live version won't show that content but I can see everything on my end in the content library. All of the files are public as well.
Looks like this was an issue and supposedly fixed early this year? I would contact ESRI support.