Army of TWO The Devils Cartel

I'm not wearing a custom mask but I'm still getting the glitch mentioned above. I'll try swapping my battlefield mask for something else and update

My cooperative buddy had a custom mask on and this unlocked just fine. Perhaps if the host wears one?

I experienced the same glitch as troyoy. I switched to try both of the first masks and the basic clothing that you start with and kept getting the Bravo Killed screen. I was playing on easy and there are not really any good solutions to this that I could find. Finally, on the 5th attempt I was able to get it. The key difference for me was that I initially was restarting from the checkpoint after changing masks and/or getting the Bravo death screen. Though the starting place is exactly the same, I decided to start at the start of the chapter instead on the 5th try. I would note that my AI partner did get run over and died so I restarted from the checkpoint again, however, it seems that if you change masks, etc. be sure to restart from the chapter start rather than the checkpoin. Then if you die, you should be able to restart from checkpoint. Hopefully this helps!