Check your source code:
view-source:https://meggittsensing.com/energy/service-and-support/repair/
There is not a single line here that points to anything in the /plugins/ directory. This is only possible if you have no plugins installed or if you are using some kind of caching. I assumme CF7 and Conditional fields are installed and ACTIVATED, so the only possible problem is that something gets cached, the code below makes me expect as much.
<!-- Include all compiled plugins (below), or include individual files as needed -->
<script src="https://meggittsensing.com/wp-content/themes/MSS/js/bootstrap.min.js"></script>
<script src="https://meggittsensing.com/wp-content/themes/MSS/js/lightbox_scripts.js"></script>
<script src="https://meggittsensing.com/wp-content/themes/MSS/js/lightbox_plugins.js"></script>
<script src="https://meggittsensing.com/wp-content/themes/MSS/js/functions.js"></script>
Have you tried switching themes?