All of your properties have synced successfully, but a page shows only some of them.
Why this happens. The homerunner-explorer shortcode takes a per_page attribute that caps how many properties render on the page. For example, [homerunner-explorer map="1" filter="0" per_page="15"] shows only 15 properties even if you have 18. The remaining properties are cut off at the bottom based on the grid’s sort order.
What you can do. Check the per_page value in your shortcode. Raise it to at least your property count, or remove the attribute entirely to use the site default.