Hi, Tehree! o/
Usually this happens when you get in some strange phasing pertinent to a specific quest. It shouldn’t persist once you are out of the area where this phasing is relevant, so if you are not seeing NPCs in places like Boralus, it’s probably stuck.
Try jumping from a cliff. No, seriously. Sometimes, death can clean this, and it should be quick, so it’s worth a try.
If that doesn’t work, contact a Game Master so they can have a look and try to clear this for you 