Event Display on Calendar

Love plugin. Having a problem with events displaying on Fullcalendar. Using the [fullcalendar] short code. Problem is unique to Internet Explorer. The [events_calendar] short code works fine, but thta isn’t what my user wants. Have de-activeted and deleted all other plugins and the problem remains.

Can anyone help us out here please……….

https://www.ads-software.com/extend/plugins/wp-fullcalendar/