I’m having an issue that is pretty major, since it entirely stops me from being able to work on UI right now. I am unable to view my UI’s in editor - both in scene and prefab editor mode.
I can see any UI related gizmos, but no UI. All layers are visible in editor. I’ve run into this issue before in the past, but restarting Unity has always solved it. Now, it does not! I am using Unity 2020.1.17f, I was using Unity 2020.1.16f and it had the same issue.
If the layers are visible and the gizmos are visible, objects are focused but you still can’t see them in the scene - have you tried rotating the camera to see if you’re looking at the back of the UI? That’s happened to me before… 
I wish that was the issue, but alas it is not 
Well, after a whole day of banging my head against the wall, I figured it out. Turns out if you disable the “opaque texture” in the URP render settings, this will break all transparencies only in the scene view, which includes UI.
This seems like a bug lmao