Stuck in volenfell AGAIN!!! Stuck in combat. Cant Leave
Same thing happens in Falkreath Hold. Stuck in combat Cant Leave
Same thing happens in Cyrodill. Stuck in combat Cant Leave
Stuck in combat is a feature that has been with us for many years.
Apparently there is no way to get rid of this wonderful part of the game, but there are some ways to deal with it:
If you get stuck in dungeons, you can "leave instance" in the group menu (at least on playstation).
Or you can travel to Imperial City or Cyrodiil (in the campaign menu).
If that's not an option (because of a queue in Cyrodiil) you can try drinking an "Essence of Ravage Health" (Emetic Russula, Fleshfly Larva, Nightshade) and respawning somewhere after you died.
If all of that does not help, close the app (don't log out! just close the app) and log back in immediately. You will not get kicked from Cyrodiil if you are fast enough.
Yeah, this has been an intermittent idiosyncrasy of ESO as long as I can remember, and it seems to have been happening more frequently recently. You can always force-quit the game client (up to and including using your OS version of the "task manager"), or if all else fails, power cycling the underlying device. Not fair, not right, very disruptive, and apparently not considered a "bug" by the developers... but you have recourse.
Had a vaguely related issue just a few hours ago: Standing idle in the "Library of Dusk" area in Coldharbour (had just completed the "Kill 10 Humanoid Daedra" daily endeavor), and I kept popping into combat spontaneously, and my companion (Ember) kept firing up for combat, rushing forward/past me by a few steps... half a second later, it ended, my character exited combat, the companion returned to idle state. Happened half a dozen times in rapid succession (on/off every 3-5 seconds or so). I got tired of it, and moved towards the nearest wayshrine. It did not occur again.
Was there something trapped by 3D clipping in the landscape immediately below me (or otherwise nearby), trying to attack over and over? I saw no evidence of anything.
This is one of several weird artifacts, since the most recent release. Par for the course, unfortunately.