Seems, these two functions are missing from the script in TFN. But since they only turn Ash's presence on or off, that shouldn't interfere with the rest of the script.
Sometimes Ash tries to keep a large distance between the player and himself when you tell him to follow after combat has started. I don't know why.
If you can't get him to move, check the console for "G.Hunters_Dead". Type it in without the "". It returns a number. If that number is not 5, enter "G.Hunters_Dead 5" or "G.Hunters_Dead = 5", I'm not sure which one, but I think the first (the other one does no harm).
Then if you talk to him, he should start the "negative zero" talk, give you the money and activate the teleport out, no matter where you are.
If this doesn't help either, then I am "mit meinem Latein am Ende"
Tuesday is Soylent Green day.