Comment 4 for bug 1387533

The package version is "4.11.1-2ubuntu2".

This is an upstream filing of my "launchpad.net" report you can find here:
https://bugs.launchpad.net/ubuntu/+source/xfwm4/+bug/1387533

Quote:

I discovered an intermittent glitch where if a window is edge snapped, the maximize button will not change to the restore button and the following behavior is experienced:

1) Left clicking on either the "minimize" or "close" buttons successfully executes the respective function.

2) Left clicking on the maximize button appears to do nothing.

3) Right clicking on the maximize button executes the maximize function.

There is a possibility that this glitch may be tied to Thunar in some way because, if my memory serves me right on these few and far between occurrences, it is usually Thunar windows that exhibit this behavior. Since the glitch is related to window decorations and affects edge snapped windows only, I filed this for xfwm4.

If a misbehaving edge-snapped window is dragged away from the edge, the same window can then be successfully maximized with the function's button by left clicking. Snapping the window again may relieve the condition temporarily or it may continue. I will watch for the result of that if and when there is a next time.

Thanks for all your efforts,
Mark