When opens the Trickster window and double clicks on a Favorite, the window should close. Now, one needs to manually close the window.
You need to click on the anchor-looking button on the top-left of the window title bar.
The anchor is now enabled (blue), so Trickster window needs to be disabled manually.
Click to disable it and Trickster will close when the activity passes to another application.
Thanks for the rapid response.