Image filename with E on iphone 13 - April 2022

I purchase the iPhone 13 in November 2021 and have taken over 2,000 photos, around January 11, 2022 when I connect my iPhone to Windows 11 by USB to copy the photos to the computer they now have almost duplicate photos, the second with IMG_Exxxx.jpg, an "E". I haven't done anything that I know of to cause this change, the first is a square photo, 4032x2034 and the second looks more wide angle, 4032 x 2268. The first is about twice the size 3427KB and 1981kb. Has anyone noticed this?