Currently, under certain (unknown) circumstances, it appears as though a Grid's Row or Column size manipulation via its adorners, can be prevented from growing in such as much as is actually possible.

See attached video; note how the first expansion get blocked at 512px, and it requires a second click-and-drag of the adorners to expand to its full possible potential.

Repro Steps:

1) Open the Z3L sample, and on the MainPage, find the Grid named 'InterfaceGrid', which is one level down from the parent 'MasterGrid'.

2) Select the 'InterfaceGrid' Element to have its Grid Row/Col adorners appear on-stage.

3) Identify the right-most column, which is a 64px column, and click-and-drag its adorner from the right, to the left of the Stage, as far left as you can.

Observe how at 512px, the column ceases to expand leftward.

4) Release the click on the Column-dragging adorner, then click-and-drag it to the extreme left again.

Observe how when done in two distinct actions instead of one, the column can be extended far further leftward.

Expected Results: A Grid's Columns and Grids can always be extended to the range that they are capable of without being 'blocked' in-motion.