Round spots on photos with clean sensor

Every time I change the lens, the photos in manual mode leave me with spots, which I can also see in the viewfinder. The same photo in automatic mode does not have this problem. To fix it I have to reset the machine. I can take pictures in manual mode until I change the lens again, then the spots reappear. The sensor and the lenses are clean, otherwise I would not get spots when I take photos in automatic mode.