Construction Symmetry attached struts break when using the "undo" function

[twich22]

As title suggests, struts still break when attached in symmetry mode and then you use the undo key at any time. 

To repeat: Build a simple structure using some symmetry. Then, attach struts in symmetry. Then build something else. Then use the "undo" function. You will see that the struts are no longer actually connected to one another, except perhaps for the "primary" strut, but not the "symmetry" struts.