I love how people are still asking these stupid questions and making stupid assumptions.
"Oh man, no drops when playing with friends, but I get drops as soon as I leave! Must be something other than RNG!" No, it's RNG. That's it. If you recorded every hour of the game that you've ever played and then analyzed it, you'd see that it's RNG. As it is, you just focus on when you're having bad luck and come to stupid conclusions.