How to get GarageBand Smart Control Screen to Show Plugin Settings

I am trying to set parameters of several plugins I'm using. The thing that is perplexing to me is that the display in the Smart Control Screen doesn't show the settings for the plugin I'm working. For example, I might see the controls for Delay Designer be displayed, but I want to change the settings for a different plugin. If I select a different plugin, its settings will be shown in a new box that pops up, but the control screen doesn't change. Is there a way to have the Smart Control Screen reflect the settings for the plugin I want to change. I've not been able to figure this one out.

In the example below, I'd like to see the settings for Delay Designer in the blue control screen area, but instead the controls shown are for the Bitcrusher. Is there a trick I'm missing?