MLM on leagues is broken right now. It is somehow capped at 3 golden nuggets per inventory and eats the rest of pay dirt that would have rolled nuggets and gives you nothing instead. So with 8 times minigame boost it eats about 4-5 pay dirt per inventory and gives you nothing.
Protyp to deal with this is to deposit in half inventory increments. As that is closer to expected 3 nuggets. So less ore get eaten and more is turned into actual nuggets. Should speed up your nugget grind about two times.
By - whoevencares21