Sig Sauer MPX 9mm PSB

[promiseofwar]

So I purchased a SIG MPX PSB in 9mm and I was lucky enough to get a Gen 1 (sarcasm), production date 10/26/15. I also received two Gen 2 30 round magazines. My understanding is that the Gen 2 mags will not work with the Gen 1 uppers. Can anyone confirm this?

Edit: I found out the Gen 2s will not work with the Gen 1.