Back out and go back in and it should update. It does do this every once in a while. My Wife's system was DL ESO update and it was stuck at 3% I then hit pause install and restarted and it was done. Sometimes it updates, sometimes it says installing without showing a percentage.
BTW...How does the new controller feel? I love it. The grip on the underside is really nice.
The controller feels really nice, but I don't have the original xbone controller to compare it to. Thanks for the tip, I knew it should have percentage shown. Not sure if I'll start the game tonight before it's fully downloaded.