Problem: You add a Search Results webpart to a page and using the query builder configure the results to retrieve and the format in which to sort or filter them. In the preview on the query builder the query appears to be returning the correct results, in the sorted format desired, but when you save and close the page the results are not sorting.
Solution: Create a Result Source on the site collection that has the same query. Then go to the page with the Search Results webpart and in the query builder choose the newly created Result Source where you “Select a query”. Save and close the page and the query should now return the expected results in the sorting format desired.