When raiders come in to my vault and start attacking my people it will show that they are in one room, but the game registers them as fighting in another room because my characters in the other room start dying, while people in the room that they APPEAR to be in take no damage. I would attatch a picture of it if i could.

I've confirmed this already and will confirm it again. It seems to happen when the raiders are in the process of entering an empty room when defenders enter at the same time. There is a brief time where they register as moving on, while their models actually stop to fight where they are.