bad chars

Hi, I use Czech language and there is special chars like: ščěř…
So I use this chars to test fonts at google.com/fonts page and there looks fine with Freckle Face font.
But if I choose this font at my WP, this special chars doesn’t work.
What can be wrong ?
Thanx a lot

https://ww.wp.xz.cn/plugins/easy-google-fonts/