Since some days, there's discrepancy between search results on Commons and PetScan search results based on the very same search. For example, a search on Commons with search string Tschubby map incategory:"Media_missing_infobox_template" currently yields 1,087 hits. Executing exactly the same search on PetScan yields between (!) 1,039 and 1,065 results (I did multiple search runs with same psid). Repeating the search on PetScan yields different results, while the commons search result is stable.