Spotlight Cam Battery not charging with solar panel

Well this is weird. One of my stickup cams on a solar panel suddenly went to 100% in a single morning (from about 88%). My other stickup cam (also on a solar panel) is still losing power. My new Spotlight cam (also on a solar panel) is still losing power. My Ring Doorbell 2 has always stayed at 100%. Is this the Ring Twilight Zone?