Is there a way to load an additional font weight so it shows up on mobile? The 400 weight of Josephin Sans shows up fine on desktop and tablet but not on iPhone.
You can tell the option to include that additional font weight, and then use CSS to apply the weight to the text on mobile. Which element are you targeting?
it looks like most of your heading content typography has been set in Elementor. Any manual edits you make to the elementor typography overwrite that set in the Customizer.
You would need to edit those headings in Elementor and change the weight for the Mobile size. Overwriting them with CSS is not really doable as each heading element is given its own specific CSS Class.