USceneComponent::AttachToComponent may not be called on client depending on replication order

If the component being attached is received first, OnRep_AttachParent will set bNetUpdateAttachment to true, so USceneComponent::PostRepNotifies will call AttachToComponent.
If the attach parent is received and processed first, OnRep_AttachChildren will detect that the newly attached component's AttachParent is not equal to this component, calling "ChildComponent->SetAttachParent(this);". Later, when processing the component being attached, the replicated value received for AttachParent will match the AttachParent on the client's component. This causes the OnRep to be skipped, so bNetUpdateAttachment is not set to true.

While debugging USceneComponent::PostRepNotifies, attach two replicated components together. For more control over the order in which the client processes the two, the priority of the owning actors can be adjusted.
If the component being attached is received and processed first, AttachToComponent will be called.
If the attach parent component is received and processed first, AttachComponent will not be called.

See additional info URL for repro.