I had to move some topics and posts around in order to prepare for part of my site to go public.
In one instance, I picked one post from an existing discussion in a private category (tl_0 can see/create/reply) and turned it into a new topic in the same category. I then moved the remaining discussion to a new private category. Lastly, I made the original category with the new discussion public (everyone can see/create/reply).
The new discussion appears in Latest, Search, Knowledge Explorer etc., but it does not appear on the category page. Explicitly setting the time filter to
All Time didn’t help and rebuilding had no effect either.