I have the MES 40 gen 2 or the Sportsman Elite as they call it. The original racks lasted me 4 years until I cleaned them with a scratch pad (my mistake). The racks in question are the replacement racks from Cabela's https://www.cabelas.ca/product/94256/masterbuilt-40-smoker-rack-accessory-kit. From MES The new racks only lasted 4 or 5 smokes before rusting at the weld joints but also were the chrome has chipped off already.
Definitely something wrong with those new ones. Mine are all like new, and some of them are 8 years old.
I'm wondering if the replacement racks are actually from some place other than Masterbuilt?
Maybe you have to go after Cabelas for them?
Bear