Pretty sure it was just a few of the first production releases where a minimal amount of epoxy was used on a few backplates. Mine was only the pitching wedge. I could lightly tap the back and it always sounded loose compared to the other irons in the set. I have not heard of any issues with the mid to long irons. BTW, Max Homa is carrying one. I play my set almost every day and the backplates are fine. Love them. I don't even think about the backplate except when I see these posts.

It is relatively uncommon. My first set of Titleist irons were 712 AP1 and have had T300 and T400 and now a combo set of T200/T350. I never had the badge come out.