When you trying to seach for song in your Library, writen by cyrillic, search results will depend of the char case, you type. On screenshots below you can see, I am trying to find song 'Я бью...' by typing 'я' and 'Я' added to my Library, in Library-Songs menu. If chars case not matching, song will not be founded. If you searching song writen by latin, it will be founded in any case of char.
Is it possible to fix?
P.S. this issue also repeats on Windows 10 application.