I am having this problem but even worse, when I log out of the game my screen is going nuts and the only thing that will fix it is the shut my PC down and restart it. I have an ATI card and I am going to try and uninstall and reinstall the drivers and see if it will fix the problem.
The video mode changes are due to the new Dedicated Full Screen Mode.
You will most likely see some "odd" large font stuff when entering the game in this mode, but should not have issues when exiting or during play (other than your mouse will be "captured" to the game if you have multiple monitors - and you can no longer keep the game up while surfing the web etc)
If updatign your drivers has no impact, and the issue are more severe than the benefits then change back to "Windowed Full Screen" This is done in the settings menu (under video).
If you cannot get there due to the issues, then edit UserSettings.txt (in documents/Elder Scrolls Online/pts) and change:
1. SET SkipPregameVideos "0" from "0" to "1"
(turns off the logos and speeds up the load time)
2. SET FULLSCREEN_v5 "2" from "2" to "1" (windowed fullScreen)
This will put you back into Windowed full screen mode.
Fullscreen setting options:
0 - Window
1 - windowed fullscreen
2 - dedicated fullscreen
I am having the same issue, left a sewer quest area in Deshaan and was hit with this bug. I had changed my video settings from dedicated full screen to windowed full screen before this happened.
Luckily, during the loading screen issue, something killed me. So I relogged, and spammed the "r" button so I would spawn at the nearest wayshrine before it would go into the loading loop. It worked, but now I'm just worried I may run into the same issue.
maybe this bug is related to the infinite loading screen we have in EU due to lags
and there is a lot of patch downloading now that can produce a lot of lag