When searching for 'community' without filters the results for Content Type Post is (161)

see https://dev.p4.greenpeace.org/international/?s=community&orderby=relevant

but when filtering by Post we get only (38) results.

see https://dev.p4.greenpeace.org/international/?s=community&orderby=relevant&f%5Bctype%5D%5BPost%5D=3

This happens because when we use filters (due to limitations of SearchWP plugin) we have to query the database also by using the WP_Query. But WP_Query does not recognize stemming so it gets only the 38 results that have the whole 'community' word in them, ignoring stem words or derivative words (commune, communities) etc.