Preview search function not working

Preview does not let me search a password protected PDF. I'm able to enter the password and read the document but the search function does not work stating that the words I'm looking for are not found even thought they are in the PDF.

I've tried acrobat reader and it is able to search, but does not highlight the words. So it gives me the pages the words are on, but I have to skim through them to find the words I am looking for.