We tried temporarily disabling the Wordfence plugin (saving all settings) and that solved the issue. We have reactivated the plugin. They should have their web developer take a look and see if any of the wordfence settings could be interfereing with the rendering of javascript. We do not want to mess with their existing settings ourselves.
Preview:
downloadDownload PNG
downloadDownload JPEG
downloadDownload SVG
Tip: You can change the style, width & colours of the snippet with the inspect tool before clicking Download!
Click to optimize width for Twitter