I’m experiencing occasional flash of unstyled text with the Adobe font Abolition. It is hooked to wp_head with a Hook Element (<link rel="stylesheet" href="https://use.typekit.net/foo.css">), and added to the Customiser via
I’m adding the font via CSS, so I removed the snippet from functions.php and it seems to be working. I read around that this seems to be a common issue with Typekit fonts, indeed not theme-related.
If the issue reappears I’ll try to deactivate the cache plugin.