Steps to reproduce:

1. Create new project
2. Create a Canvas
3. Add child Image to Canvas
4. Add child Canvas to Image
5. Create prefab out of previously created Image
6. Delete Image instance from hierarchy (so that only a prefab would be left)
7. Now scene should have childless Canvas
8. Instantiate image prefab as a child of Canvas
9. In scene view, notice that Canvas > Image > Canvas's RectTransform values aren't same as before

Additional note: Moving nested canvas in step 4 doesn't update graphics (image doesn't move)