Not sure if this occurs in the PC version as well, but in the PS4 release the text boxes from NPCs slowly shift either down, or up off of the screen each time you talk to someone. After about 4-5 cutscenes, or NPCs simply talk to you, the box is unreadable, and has to be moved back up. While it isn't a major bug, it does get pretty annoying; specially if you're using a controller where you'll have to manually shift it up using the touch pad. I've been using a mouse and keyboard lately (which makes it easier to click and drag), but I'd love to see this fixed sometime.

Also, yes, I've tried setting the location of the chat boxes with the hub layout, but that did not work. The best way I found to avoid it is by moving the text box to the center of the screen, covering the NPC. It still moves slightly, but it does still move... Towards whichever side of the screen it is closest to to be exact (if its closer to the top, it'll move towards the top).