Mirroring assembly results in sub-components out of position

[billg.project]

I have an assembly that contains mulitple sub-assys and components. When I mirror the assy Through Truss Leg, an element of this assembly is out of place. Namely one of the 10" C channels. Fusion file is attached. Thanks in advance for the help.

[etfrench]

You have yellow warnings in the Timeline.  These should be fixed before moving on as they can cause failures later in the Timeline.

You may have better luck by using joints to position each of the assemblies.