Thanks for the report on this. Unfortunately this is a consequence of how we paginate searches and how WikiVoyage is ranked in results. You'll notice for most search terms WikiVoyage does indeed show up on the second page of results, but since we already have loaded the first page it doesn't get pinned. I don't believe there's anything we can fix here as this is just how results are ranked, loaded, and displayed.
Have you tried our Bangs feature to search WikiVoyage automatically? That might be helpful in your use case 🙂