I think I found a bug in SceneView.cs in OnEnable, in version 1.1.4. You are destroying the Canvas before the GraphicsRaycaster. I got an exception from unity when doing it in the existing order. Switching the order seems to have corrected the problem. Does this seem like the correct fix to you?
Hopefully this helps others who might be seeing the same problem.
(Love your product! please keep up the great work!)