Reset theme to system default unintuitive in Zorin Appearance

In the Theme tab of the Zorin appearance app, once the user changes the Application or Shell theme, it’s not intuitive how to reset it back to system default.

In order to reset, I’ve had to click the “Background” option to switch it back to light theme which reset my chosen system color.

It should be back to alter the Theme back to system default without resetting the selected Accent color.