Hi Tomas,
Go to template settings -> typography, set the font subnet to latin-ext then try again
Screenshot https://imgur.com/a/1Ca3g
Reply To: Font issue - Czech special font ščřž
Joomla! name is used under a limited license from Open Source Matters in the United States and other countries. WarpTheme.com is not affiliated with or endorsed by Open Source Matters or the Joomla! project