Foam delaminated / crumbled - BlackHawk Desert Ops Boot

I had 2 pair of these over about 3 to 4 years wearing them to work in aircraft manufacturing builings and walking nonstop all day long. Wore them in snow, and in the summer on flightlines and they were solid, but the last pair i got within a few months the foam between the vibram bottom and the boot body itself started to literally disbond and crumble. There was nothing wrong with the boot body or the tread, just the foam inbetween was garbage. No chemicals, fuels, acids, or anything had gotten onto the boots. Another buddy of mine had the same problem. The foam on his started to crack and chunk apart.