I can't stand it when sites do that (blocking paste) but I don't think that is what's happening here. It's just their placeholder text "Password" that is messi

I can't stand it when sites do that (blocking paste) but I don't think that is what's happening here. It's just their placeholder text "Password" that is messing things up. Try long-pressing just on the left of the 'P' of the placeholder. That worked for me after a few tries (on Android).