Forum Discussion
Threads on this issue:
http://answers.ea.com/t5/Dragon-Age-Inquisition/my-party-members-never-want-to-use-their-abilities/m-p/4056282#U4056282
http://answers.ea.com/t5/Dragon-Age-Inquisition/Party-AI-has-stopped-working/m-p/4048630#U4048630
http://answers.ea.com/t5/Dragon-Age-Inquisition/Companion-ai-not-using-spells-or-abilities/m-p/4045484#U4045484
http://forum.bioware.com/topic/527595-game-breaking-bug-on-x1/
http://answers.ea.com/t5/Dragon-Age-Inquisition/Companion-stopped-using-skills/m-p/4061403#U4061403
http://answers.ea.com/t5/Dragon-Age-Inquisition/Companion-are-not-using-skills/m-p/4042601#U4042601
Hope this gets fixed. Super annoying bug.
I think I found a solution.
From Xbox menu go to My games and apps.
Press start on Inquisition and select manage game.
Scroll right to your profile and select saved data.
You should see "delete from console" and "delete from everywhere"
I deleted from console, then started inquisition again. Upon starting up it synced game data (downloads the saves from cloud storage) I loaded my most recent save and boom.
Companions are using their abilities again.