I noticed that there are no topics counted on the dropdown menu. Not sure why this happened. I only noticed it today. Oddly enough, new site feedback and promotions are still counting.
I checked the other dropdown in All, but that is perfectly fine.
It is expected behavior - the top level categories should not contain any topics (#site-feedback and Promotions don’t have subcategories). You’ll see that the subcategories do correctly display the number of topics: