We do show “Uncategorized” globally below the topic title.
However, when you pin a post globally the category “Uncategorized” disappears, other categories are shown correctly for pinned topics in topic lists.
Also “Uncategorized” is displayed for not pinned topics as you can see in the screenshot below.
Both first globally pinned topics are “Uncategorized” but don’t display it (and it’s not in the rendered HTML, the div
link-bottom-line is empty).