Wow, I thought I was nuts until I sussed out exactly when this happens…
Here’s a category banner. This is a category that anyone (anon visitors included) can see. I get this banner if I pick the category from the category dropdown in the site navigation, and if I click on a category label/box below a topic title. Which is exactly what you would expect to happen:
But I have this other category which has some group-based security on it. Notably “anyone” cannot see this category. If I navigate to this category (by picking it from the category drop-down, or by clicking the category box/label below a topic’s title) I don’t get the banner:
If I just hit reload in my browser, then the banner appears.
Note that I’m logged in as an Admin. If I impersonate a normal user (a level 1 user who is in a group that gives them See for this category) the behavior is the same. Navigate to category, no banner. Hit reload, banner.