I think you'll find really difficult to find a camera that controls WB identically between auto and a specific preset (whatever it is). Adjusting the WB automatically is a tricky thing (why do you think so many cameras can't handle tungsten or fluorescent light very well?). When you choose a preset WB, you are forcing the camera to use a certain Kevin value. However, when you shoot in auto, the camera evaluates the lighting and chooses the value based on that. Thus, the cool/warm variation will exist most of the time, specially if shooting in overcast/shadow conditions because in those conditions the Kevin value is way higher in order to minimize blue cast in shaded areas.