When typing a search term using the search widget, the results for posts show up well but, if a page entry shows up at the top of the search results, it produces a duplicate of the page title. This is the case when setting the page title to 'default title' or when setting it to 'custom title'(and entering the custom title in the appropriate field in the page editor) .

If the page entry is second or lower in the search results, the page title is shown correctly, only once.

problem was with a plugin i was using