A problem was present in Copernic version 8.0.0 and 8.1.0 which prevents searching using an exact phrase for file names if we omit to specify the file extension for some files. This happens because the word and the extension surrounding the dot have not been segmented into two separate words. This will be fixed in the next release.
For a file named "File Name.pdf", searching for "File Name" with quotation marks will not find this file.
Searching for "File Name.pdf" with quotation marks will find the file.
Searching for "File Name" without quotation marks will also find the file.