Search function not working properly

I noticed only yesterday that if I search on my site for anything (say, Shakespeare) with more than 30 items, I get 'Shakespeare?deepsearch=Shakespeare' and the result 'No books found'. So I'm in effect restricted to the 1st 30 items & can't turn on to the next pages either by hitting 'Next page' or by clicking on '2' or '3' or whatever number.

Same applies to searching by tag eg FrLit

Already reported: https://www.librarything.com/topic/332202

Closing as duplicate.