Mirrored Visor looks like it's flaking?

Hi everyone. I got this mirrored visor probably about a month and half ago. It's for my HJC rpha 71 and the visor is a HJ-40. I clean it with a proper visor cleaner from motul (which is supposed to be safe for every type of visor, including mirrored visors) and a soft clean cloth every single time it gets dirty, and everything seems fine except for it looks like the mirrored coating is flaking up the top, or rubbing off or something. I was thinking it could be the cleaner or cloth, but why would that happen now, and why only at the top? Just looking for some insight into this as I'm always trying to look after it properly and am very confused. Thanks