Tweening margin causes opposite margin to jitter

[clever sierra]

it doesn't create this problem if I tween the right margin

also happens with lerp. I've noticed in the editor moving the left margin updates the position, but moving the right margin does not. I suspect this is related

setting the scale x to negative, and adjusting the right margin instead works for now. Will leave this here for a little while incase there's a better solution, because this messes with other behaviors

[unborn osprey]

I think you are doing your margins wrong. You should set them in the theme and inherit from a parent control.
The right margin in the box you are using is left margin value +right margin value. The theme uses a -value from parent right margin which prevents this jitter.