Okay, I learned from another thread and tested myself.
Long story in short, EXP multiplier is not working once you enter FFYL/dead and as Moze entering her IB!!! It will bounce back to M0 with NO extra exp for fighting M10 mobs. The only way to reset this back to normal is to ‘save and quit’ the game.
This is ridiculous, why is this even a thing?! I think GBX shall really think about remarking this game as EA stage so that we players could accept all the stone age bugs and issues!!
It’s easy to be observed so I didn’t even bother to put a video here, just kill whatever mob and do the same again after FFYL.
GBX, please fix this, I mean you could have a say in loot drop chance, since we won’t be able to know the exact value you put in there; however, this is obvious a serious flaw and a real game bummer.
EDIT: FIXED, thanks so much GBX!