Gradient Mask Rendering Bug

I have a container sprite that houses some child sprites. The container sprite is masked with a sprite that has an alpha gradient. Upon tweening the tint the causes the mask to render incorrectly. I am also tweening the position of the child sprites. However, with the tint tween disabled, the mask behaves normally and does not cause a rendering issue.

I’m guessing the gradient mask is being updated correctly when changing the appearence of a cached child sprite. Moving the position and scale is ok, because that is not causing a redraw.

Any thoughts on soultions or workarounds would be great!