Semantic queries are cached to prevent the load of constantly re-running them. The cache has a time-out of about a day or so. Therefore, changes to semantic properties may not be immediately reflected in pages that show queries using that data. You can do three things:
1) Do an Edit>Save of the page with the query on it. This will recalculate the page, even if you don't change anything. If you don't change anything, it wont even record a change in the page history.
2) Add "&action=purge" to the page URL and reload it. This will dump the cache and force it to recalculate the queries.
3) Wait and let the cache timeout and be recalculated. Could take up to a day for it to happen.
