Has the game has always done this & I just never noticed or is this a bug?
If I anchor a control to guiRoot, in any way, say BOTTOMRIGHT to BOTTOMLEFT and then move the control around the screen it doesn't just update the offsets, but it also changes the anchor points. For example if I move the control near the top left corner of the screen the anchor becomes TOPLEFT to TOPLEFT, move it near the top right corner of the screen and it becomes TOPRIGHT to TOPRIGHT, exc..
If I resize the control it seems to change the anchor points as well. Dragging one side of the control seems to change the anchor to the side/direction your dragging it in. Grab the bottom of the control & drag it up and it reanchors TOP to TOP, grab the left side & drag it to the right and it reanchors RIGHT to RIGHT, exc...
It seems like a bug because if you use ResizeToFitDescendents the controls growth direction depends on its anchor so moving it around the screen causes the control to grow in different directions. As it stands I have to reanchor the controls every OnMoveStop so it keeps the correct anchors & grows in the correct direction.