[4.5.1, Video and Repro Project] I had to revert to 4.3 Again, Set Simulate Skel Mesh Bug On Client

Digging a little deeper, the issue seems to be caused by the following:

if (OwnerComponent->AttachParent)
{
	OwnerComponent->DetachFromParent(true);
}

Located in BodyInstance.cpp in the SetInstanceSimulatePhysics function, if I comment it out, then it works exactly the same as my workaround above.