When undoing a Send/Receive connection and then adding the Bus connection again, the connecting patch cord is missing.

To reproduce:
- Open attached project and launch "test" scene
- Open Audio Mixer window
- Make sure that "Show bus connections" is and "Highlight bus connections of selection" enabled in Audio Mixer
- Select Audio Group "1"
- Go to Inspector and connect the Bus to "2/Receive"
- Observe the patch cord connection between the two groups
- Press cmd+Z to undo
- Observe that the patch cords are now gone (expected behaviour)
- Go to Inspector and connect the Bus again to "2/Receive"
- Observe that the Bus is connected, but the patch cord is missing on the audio groups