I was having a similar issue today. My team works in a shared Express project, and some of the brand kits and libraries in the project disappeared for me and one of my teammates- but they were still showing up for other team members. I created a new brand kit in the shared project, and that must have reset something because all the missing libraries and brand kits showed up again after that. It didn't fix it for my teammate at first, but she tried creating a new brand kit as a test and that fixed it for her too. Hope this helps!
Thanks for your response and for sharing the screenshots. Can you try logging out and logging in again to see if that helps? Also, please ensure that the network endpoints listed on https://adobe.ly/4cVhmrx are allowed.