"Search" and speakscreen are useless

I am using IPhone 5s. After updating to IOS9, "Search" and speakscreen are useless. Can't search any words or numbers in the files. Speakscreen shows "There is no word can be spoken".

I found many problem in iBooks:

1-Some PDF files become messy code;

2-It can't work background when I use speakscreen;

3-ePub files are difficult to open, it scrolling when I open a large ePub file and stay still.

I need speakscreen to read the books, is any one can help me?