Font issues with polish letters

Hello

I finished my website on my local server. Everything is okay with fonts when I’m logged in, and all fonts look okay with polish letters. Issues start when I’m logged out or I’m using my website in incognito window. All fonts are changing polish letters to the default font and I can’t do anything with it. I’m using themify ultra and I set up it in my themify options to use latin expanded but it doesn’t work. Any idea?