Since the most recent patch I find I can no longer rebind my controller buttons. At all. I am using a Microsoft Xbox controller on PC.
I suspect that the recent changes to the Interact button (re: new Symmetra might be at fault here).
I put a detailed Bug Report in the appropriate section. Please detail your own experience with this. Even reports that counterindicate mine would probably be helpful to Blizzard in zeroing in on this issue.