After Back Arrow from Map Page Widget Gone

After the widget map is clicked and the larger map page displays, clicking the browser back button displays an archive without this widget in the sidebar!

Although the home page is at http://www.habershamtheater.org/hct/
I see the back button takes me to http://www.habershamtheater.org/hct/category/productions/
This is probably the way the theme works, but I still don’t understand why the widget disappears.

Reloading the home page produces the widget again.

Lane

https://wordpress.org/plugins/google-maps-widget/