Thank you for reaching out. If I heard you right, you are having trouble installing fonts in XD. I would like to know if you're trying to activate Adobe Fonts from the Creative Cloud desktop app or you're installing fonts from outside. Are you running on the latest version of XD (28.8)?
The fonts were installed externally, and no Creative Cloud import was attempted. XD is the latest version. In PS, AI, and AE, using so many fonts will only freeze when loading. XD is stuck when zooming in and out, and moving the window.