Coupons are harder to get

i just bought some ZP and i bought some crates but in this "new black market" the coupons are much harder then the "old black market"
on the old bm if you buy 10 zp crates u get at least 8 Coupons
now with the new BM if you buy 10 crates u get 2 coupons

is that a bug ?