The result of the Attach target change operation using AttackTrack's ContextMenu varies depending on the flow

At present AttackTrack's context menu has three patterns of Attach target change flow

1. Change constraintBindingID
2. Use ExsitBinding
3. Use NewBinding

However, 1 and 3 can correctly change the target, but the result of 2 is different from that.Specifically, the attachment in the selected section is not changed, and a new section is newly added to the end.

This is because the section of F3DAttachTrackEditor :: ActorSocketPicked becomes null when using ExistingBinding.Because it becomes null, a new section is added by F3DAttachTrackEditor :: AddKeyInternal via AnimatablePropertyChanged.

If we pass a Section to FActorPickerTrackEditor :: ExistingBindingPicked like FActorPickerTrackEditor :: ActorPicked , it may be resolved

See description.