When members add event’s iCal to their calendar (both internal and external event), there is no info about the event in the description (nor link), there is only link to the community event. 

In that case, members who add the event to their calendar, and the event is e.g. in Zoom, to reach that link, they need to follow the community link in their calendar event description, potentially log in the community, and only then they see the link they should follow. It’s quite a number of clicks to land in the event. 

Also double-check; reminders are sent only based on your calendar you import the event data to, there is no Gainsight reminder, right?