in your case, if you don't see any gap in your exposed foam then it might just be from the lace loop that weren't punched thoroughly.
always wondered and wanted to ask the same question on how other's are holding up. a small chunk of foam from the bottom V on the back collar on my sail came off, not sure if im wearing them too tight/loose that the abrasion rubbed them off. worse on the left pair presumably the pressure i put on them resting while i drive. they look fine aesthetically when laced up so im not stressing too much (enough to comment tho lol).