SharePoint Search REST API not returning all subsites

This query is not working !!! I have 10 subsites, but it only returns 2 of them.
https://serverURL/_api/search/query?querytext='path:"*********"  contentclass:STS_Web'&rowlimit=20

Solution is to add &trimduplicates=false at the end of the query.
https://serverURL/_api/search/query?querytext='path:"*********"  contentclass:STS_Web'&rowlimit=20&trimduplicates=false