Has anyone had this happen when using an Autorun to take flats? I am using auto exposure and a white T-shirt, these particular images are using blue sky for lighting, but I have had the same issue using an IPAD with a blank white screen. I'm still relatively new to astrophotography so not sure if this is normal but my photography experience says that images with the same lighting and shutter speed should expose the exact same every time. I have taken manual flats in the past with my camera and not noticed the same thing occuring.
Not sure if it matters but my camera is a Canon R5