Gray shadow area on iPhone 14pro photos

i recently updated from an iPhone 11 to a 14pro. I'm very much an amateur when it comes to photography and all the terms/tech. I take product photos for my Etsy shop. Despite no change in my lighting set up (DIY lightbox with LED 5000K bulbs overhead in room and in a separate light aimed through a diffusing panel in the box), my photos now have this vertical gray shadow overlay. It is not visible except through the camera and if I move the camera from side to side the gray shadow area moves with my camera. Sometimes it is in the middle of my subject, most often it's on one or both sides. Occasionally (about once out of every 12-15 shots), I can adjust the exposure before taking the picture to eliminate it. But most often, despite trying to adjust the exposure, redirect the light, etc, etc. it is there. Post edits never fully get rid of it and my photos look dark where the shadow is. Additionally as I am setting up the photo, the display will look good (no shadow), then it's as if the camera adjusts itself and the shadow is back. My husband upgraded the same time I did and his does the same thing. I've turned off the setting "view outside the frame" without any change.

I did not have this issue before upgrading and nothing else has changed.

I am open to other suggestions to try... it's been very frustrating.

Thanks! Photo included to show what I mean. (these have not been edited - just attempted to adjust exposure before taking the photos)