After giving Dude that stash of mushroom brew, you were supposed to drink with him, and once it's done, follow him to his house in Core City.
The thing is, if I, say, been playing for a few hours or just reloaded a save up to the point before drinking with him, the game would just freeze with the dialogue window popping up but I can't do anything. Before dialogue window pop-up, a cutscene-esque sequence should've play out with Dude entering his house and our character following him.
If I loaded a save fresh from launching the game, this problem won't occur, the cutscene will plays out and the quest will goes on.
