After a bit of troubleshooting, it turned out that the reason behind this was quite simple - in our template overrides for article pages, we were using the following variables to render the intro text and full text of an article:
We render these separately for styling purposes.
The problem occurs because unlike using the alternative route of
The former do not automatically fire the content plugins - and hence the Mautic plugin doesn't get triggered.
What we found we needed to do was to add the following:
or in the case of full text:
in order for our content plugins to be fired on article pages.
As soon as we implemented this, the content plugins were able to fire on these article layouts, and our Mautic forms and dynamic content started to be rendered!
Hopefully this might save other developers much head scratching and chin rubbing!