I was just having the exact same problem and couldn't seem to find any solutions online...
No guarantee that my problem is identical to your own, but I figured mine out.
My drop down wouldn't seem to update even though the version numbers looked good. For me, it was human error. I had two views that looked almost *completely* identical. When I determined that it made sense... I was updating the list in View 1 but not View 2; this made it appear that the list was not updating, when in reality it was.
That was my solution though! You might have a deeper technical problem, but give that a look.