There are differences between how Select behaves wheatear its set to single or multiple mode. When its set to multiple you get the nice label that acts as a placeholder until you pick something, but in single select mode if you use a label it interferes with the Select since there is no blank "not set" state so the two strings of text are on top of each other.

Since this is not strictly tied to the underlying select element I think there should be an empty "not set" state option available. This would allow the labels to have a consistent behavior plus you don't always want something set by default as it is now. Yes you can create a dummy option "Select Something" but why not build it right into the component so its appearance and behavior are the same as other inputs. It just doesn't feel right as it is currently.