Hi there,
Other discussions can be very relevant, but unfortunately it can be pretty hard to find an exact code that would work on your end, especially since most of the themes are having a different structure.
It’s possible that you haven’t loaded the font correctly, and it works on your desktop because you have it locally installed, while on mobile its not.
It would be helpful if you can share your website link, and indicate which is the font that is not loading as expected.
Cheers!