someone else had that issue..
And I think it was on here (not the Acadia or Traverse).
I believe they put some silicone/glue or something- to hold the little ball from sliding out of its socket..
This was me! I had this happen to my E and have no idea how or why.... I could not find anything physically wrong on the inside of the door... the wire link has a little ball on the end which seats itself into the handle section. Whenever I re-seated the ball the door handle would pull and work perfectly WHILE the door was still apart, but as soon as I started snapping the door back together, the ball would fall out again!
I set the ball back in, and used a bit of hot glue to hold it in place, and its been working great ever since.