Hmm, I think it works fine on my forum.
For testing, I used a topic that was created about a year ago in a private category. I used the admin wrench to set a timer for publishing.
Once the topic was published, the timestamp was updated, and it appeared at the top of /latest.
Do you notice anything that you do differently?
To fix the topic you published, you can try to manually change the timestamp or use the timer to trigger an automatic bump.
