I don't know what the settings are exactly, but if you aren't actually changing the exposure compensation the camera might be adjusting the values to normal so not an actual exposure change. Just a guess.
EF boost is off. I'm using M mode and Auto ISO. I think I thought it out, is it right that there will be no adjustment when the exposure is more than 3+ and less than 3-? If that's so, there is no problem.