In the attached vsp3 file, there are two wings, one which is derived from the first one. When adding a spar into the derived wing, the spar in the right side of the wing is drawn in the correct position, but the spar in the left (symmetrical) side of the wing is drawn 1 unit back from where it should be:

The main wing has Xloc = 1. The derived wing has "Attach to Parent - Translate - Comp".

If you change the parent wing's Xloc to 2, the span moves to be 2 units from where it should be. The incorrect location on the derived symmetrical wing is determined by the Xloc in the parent wing.

If you switch Attach to Parent - Translate - None, then click "Reset Part Display" in the FEA Structure dialog, the spar goes to where it is expected.

issue254.zip