I've noticed that if an app is locked to the launcher the issue does not occur. I had this problem with gnome-terminal and I had 'lost' several terminal windows. I dragged terminal from the dash and locked it to the launcher and then suddenly all the existing terminal windows were dissociated with it and were also in the alt-tab menu.
I've noticed that if an app is locked to the launcher the issue does not occur. I had this problem with gnome-terminal and I had 'lost' several terminal windows. I dragged terminal from the dash and locked it to the launcher and then suddenly all the existing terminal windows were dissociated with it and were also in the alt-tab menu.