working off some Motion templates that came from our graphics department and need to do some tweaking. However, they used a mask to reveal some text and animated its x-scale to unveal the text. The put the anchor point on the right part of the mask so it spreads out to the left.

However

it needs to be dropoed down a but the Y value on position is greyed out? no matter what i do, i can change it?! my workaround was to move the y-value of the anchor point but am confused as to what is going on? anyone know what this is??