Currently, if you have an interaction window open for one NPC, and then right-click on another to speak with them instead, nothing happens. You have to close the already open window first. What should happen is, upon right-clicking a new NPC the current interaction window is automatically closed and that of the new NPC opened.
It’s not a gaping hole in the UI, but it’s little things like this that make a game feel polished and keep you best immersed, which is actually quite important. As it stands, every time I try to switch from one NPC to another I’m immediately brought out of any groove I’m in and into a state of hyper-awareness that I’m playing a video game.