Not tried the dynamic typography manager before, so I did today. Seemed really good, changed fonts, looked good in the customiser screen, but after publishing, all my fonts were italicised and not what I’d selected. I used Yellow Pencil CSS tool, so I looked in the custom CSS there and there was nothing to italicise the fonts. Viewed on different browsers, same result. Cleared browser and site cache, same result. I then changed some fonts via Yellow Pencil and they worked ok, but some are still italicised. Would rather clear all the yellow pencil CSS for font change and use typography manager.
Can’t see how to revert back to the previous way of changing fonts either. Removed all fonts in the typography manager thinking that might take me back, but it hasn’t.
Logged in, or logged out am seeing the same, clearing cache etc. Only time the changes seem to work is when I’m in the customiser screen. With your screenshot the site heading text should be using Comfortaa like the post heading title text. The body font should be open sans.