One of my forums says “No Topics” under the “Last Post” column.

I have five forums on my forum page, and one of the forums says “No Topics” under the “Last Post” column. But the forum actually has 8 topics and 67 posts. This seems like a glitch in the system, so it seems important enough to seek support for. My forums are private, though, so sharing a link won’t work here. The last post in the forum in question was made by me about four months ago. This “glitch” has been present for several weeks at least (I’m not sure when it first appeared). Over that time span, the style pack has been updated multiple times and I’ve purged the cache a number of times, but the problem remains.