Hello,
We are using the latest Pro. Originally the site was created with X 4.x and the main nav menu font size set in the theme options many years ago. The fonts for both the top-level links as well as the sub menus are a bit too small. When I go to adjust them in the theme options, I can set a new top level font size and see it preview, but submenus font size does not resize. We are also using Uber Menu. I’m not sure if this is an issue with a Uber Menu setting or something else. I looked through both the Pro theme option for the header/typography and Uber Menu and wasn’t able to get the submenus to change the font size. I also have never been able to inspect the X/Pro classic header in my devtools so I can’t really see what is going on there.
I’ll leave the url in a separate private note.