Hi and thanks for your help and post.
I am not ware of any customisations that have been done to either the plugin or the Pro theme. All we have ever done is to add some CSS, but this has been put in Pro > Theme Options > CSS or in the MEC Plugin > Settings > Custom CSS. I have tried disabling these but the same issue remains.
I deactivated and then deleted the MEC Plugin and checked that the folder had been removed from the file list. I then downloaded and installed version 4.8.3 but the issue remains.
I have another site which uses Pro and MEC and on that site the shortcode works perfectly and as expected, therefore the issue would appear to be something on this site.
I have spoken to MEC but all they can suggest is that I do a fresh install of Wordpress, install and activate their plugin and then install the other plugins and restore the data. I think this would be a last resort resolution.
UPDATE:
I have installed a fresh version of Wordpress on the same domain, added the MEC plugin and Pro Theme and I am seeing the start and end time as expected.
Can you think of what might be causing the issue on my original website. If not, is there an easy way to move all of my posts and pages from one sire to the new? Do I also need a new licence on the meantime or am I able to use the same Licence, the new url is a subdomain - dev.modburyteam.org
Many thanks
Alex