I found the problem (my bad of course!), but I must have missed the flag when looking at the record in the DB.
It turns out that this was "Expired", then relisted, and required approval. But it wasn't in the Approval Queue. It was in the Expired Queue awaiting approval. Oddly, a whole bunch of ads were in there, so I am not sure how that works. The original settings did not require approval of ads for members of specific
VB usergroups, and the ads always appeared without any approval from an admin.
All is well that ends well, and that ad is now showing again. Strange it would show in the recent feature block but not in the category. I wouldn't think it should show in the recent block either until it is approved.
Thanks for looking into this.