Just had a similar experience. Changed font (Google Font) using the customizer. Result was New Times Roman site wide.
Looking at the CSS, root and a specific element. My font was in the font variable correctly; specifically --fontFamily: M PLUS 1p, Sans-Serif;
The element had the variable set font-family: var(--fontFamily);. Great.
Yet we have the wrong font. Checked Google font loading and yes, that’s all correct.
Last check, attempt to wrap the font in quotes so the spaces can be processed.
:root {
--fontFamily: "M PLUS 1p", Sans-Serif;
}
Added this via Customizer CSS for now and font is working. This might help someone with fonts not working, but also hopefully we can get a fix in here for the theme in general.
Best!