Ještě může být problém s velikostí souboru TTF:
Single ttf for all languages:
Another reason why a single font resource cannot be used is because all modern
font formats, such as TrueType and OpenType, limit the number of glyphs to 64K.
Unicode currently includes well over 100K characters, meaning that multiple
font resources are a necessity.
https://github.com/googlefonts/noto-fonts/issues/13
---
Nebo upravit některé z těchto:
Fonts that support the "czech" language
https://www.cufonfonts.com/fonts/list/language/czech/