Fuselage doesn't update attached symmetric part location [Beta Branch]

How to reproduce:

• Grab one of the mirrored fuel tanks and change the length via the shape tool.

See that the other pieces attached to it on the other side do not update location.

https://www.youtube.com/watch?v=RVsgnK-EhS4&feature=youtu.be <---- Video of the bug in action.

I'm trying to make it a point to provide a video with every bug now just incase I word something wrong, or it's too confusing to understand.