Transform scale should get set to (1, 1, 1), but Width and Height should be set to some higher value instead. For example if transform was 300, 200, 1, then you will end up with 1, 1, 1 for transform, 300 for width, and 200 for height.
Make sure to enable all your widgets at least once so that the upgrade process takes place. Disabled game objects and non-instantiated prefabs do not get updated. Just follow the upgrade video.