calendar not populating

I have been using the Ajax Events calendar on a clients website for quite some time. All of sudden, the events aren’t showing on the calendar. The only way I can make them appear is to click the arrow button to go to the next month. Once I do that, I can click the back arrow, and everything appears. It’s all there. It just isn’t showing when I land on the calendar page. https://www.northernharbour.com

https://www.ads-software.com/plugins/ajax-event-calendar/