If I click one of the other pages I get a full list of topics, but if I click back on 1, I get the same 3 topics. So I'm not sure if I'm missing results or if they continue on the next page.
It's a known bug, and we have no idea what causes it. The bug makes each page on search results have a random number of topics. Can be anything from 1 to whatever your maximum is set as.