Gantry5 & Shortcode Gallery Plus Plus

I am using the grav-plugin-shortcode-gallery-plusplus which is brilliant. I am struggling to incorporate it with Gantry5 layouts, I have added it to the layout via the Custom HTML particle with the Shortcode option enabled.

The plugin seems to initialise as it creates the top tag, e.g. <p id="282284594"></p> but nothing else. Am I doing something wrong?

Since no-one has replied here yet and this is quite a specific setup, I suggest asking in the plugin's issues. Or if you are lucky, the plugin developer might hang out on the discord forum and you can ask them directly.

Try to copy all the content of the file named "gallery-plusplus.html.twig" in a Gantry5 custom HTML particle and remember to tick "Process TWIG" in the Gantry 5 particle
You can find the file to be copied in the folder of the plugin (/templates/partials)

I will give it a go.