Fader is stuck after selecting a customized component - please see attached video for details.

To reproduce:
- Open attached project and launch "test" scene
- Double-click on "New AudioMixer" asset and dock the Audio Mixer window
- Select "Drums" channel strip
- Hit Play
- Press "Edit in Play mode"
- Drage the VU slider up and down
- Go to Inspector and select one of the customized plugin components
- Go back to "Drums" channel strip
- Observe that you can no longer drag the VU slider up/down