In the beginning of my game I have the player chose 2 Actors names, the hero and the Hero's GF.
the hero is in the party but the GF does not join the party till later, when the GF joins the name goes back the DB name
how can I sort this out?

If you are changing the right Actor ID names for both the hero and the hero's girlfriend, then it will stay that way inside the save files. The default name will always stay the same in new games. Are you sure you're changing the right name, and are you continuing from a save file or starting a new game to test it?

starting a new game, it happened to the hero but I fix that, what I had is no Actors in the party at the start of the game and I had a long cut seen with talking using \n[X]'s but when I add then to the party the names go back to the default, I fixed it by adding him in the party at the beginning but he shows up in the cut seens .
I'm trying different things at the moment

Edit____________________________________________________
I Fing fixed it, The problem was the "Initialize" tick box was ticked on the "Change Party Member..." Button, I unticked it and won it works

Most likely what you're doing then is adding them with the initialize box checked. This restores it to default values. Just uncheck the box and it should work.