Fonts problem

Hi,
I have problem with fonts with RESI theme. I chose “Lato” in the customizer which is supposed to have Polish letters. However it doesn’t work in post titles. I also tried to use caps but it didn’t help either.
My blog is https://vegeluv.org/blog/
I tried to find the font section in style.css sheet but as it’s built into the customizer I think it’s not there.
I also use the same font on my other website and there it works ok.
Help please! ??