There seems to be a bug in the Toolset Maps plugin. The bug only reveals itself when "Clustering" is enabled. As soon as you take this out of the shortcode, the map then works as expected.
I've disabled all plugins, flipped to a base theme etc but the bug is still there and causes various Javascript errors.
Yes of course, when I add the map shortcode without the clustering the map displays fine. It’s only once I add the code with clustering that it breaks everything on the page and throws a load of JavaScript errors in the console and won’t load any other scripts. And the map doesn’t show.
As I say, it can’t be a theme issue as I’ve tried swapping to various simple themes and the issue still happens.