It is helpful to always include close ups of both sides of the coin as well as the area(s) in question, as there may be tells that will help us assist you. Looks like a retained lamination, but without more pictures hard to tell
I posted a shot, albeit of questionable cell phone quality, of both the obverse and reverse. As well as the microscope of the reverse, where I thought the error might be. What else might be needed? Appreciate any opinions!