Why can I not choose my text style?

When I try to click on a text style from my library nothing happens and the text style doesn’t change. It works weirdly when I choose the body text style, but not with the headings. Any advice?

@Manuel_Stocker Some ?s – is the font you’re using in the style a default one? Or is it one you’ve installed?

Also, it travels across all body text, correct? So if you try and use it in different files, the behavior is the same (I’m assuming it’s a library and not local style).

Not sure if reviewing this page will help (if you haven’t already), but would recommend taking a look: https://help.figma.com/hc/en-us/articles/360039957034-Create-and-apply-text-styles