What do you mean "fixed"? The broken part earlier was that you could get on mountains through endless jumping - engine limitation of sorts that were "fixed" in FONV using invisible barriers. Not a very popular fix for obvious reasons, so I rather hope we slip and fall off and hurt ourselves for trying, compared to success by idiotic jumping.
What they did on FNV wasn't a 'fix', if anything they broke it even more.
I tried to jump over a clearly small rock to get to a road. It was 100% visible that I could pull the jump, if not over-jump the rock. Then the moment my feet hover over the rock I stop mid flight; a rock on a seemingly innocent place had a invisible barrier. :sadvaultboy: