SearchApi will not let me look for the exact file name

I want to do a search using searchApi based on the file name. I have created the complete index on all normal fields, such as the body of the title and the file. The description. That works well. But when I added the filename to the search and I also rendered the full text. This will not allow me to search by exact file name. Do not have the idea why it does not work on the file name.

Please help!