Brushes Imported Into Fresco Not Appearing in Creative Cloud Library

Yesterday I imported a couple of Photoshop brush sets into Adobe Fresco that I bought on Gumroad. They work fine in Fresco, but they don't appear in my Creative Cloud Library (or when I go to assets.adobe.com on my iPad), so I can't rename any of the brushes or delete them if I want to. I've tried signing out of both Fresco and Creative Cloud and then signing back in, force quitting the apps, all the obvious stuff, but the two brush sets still don't show up in my Library in Creative Cloud. How can I get them to appear there?