Problems syncing my Google Calendar Feed

I am trying to sync a Google Calendar via ics with my site using All-in-One Event Calendar. I had the lite version installed, and it worked fine. I upgraded to the standard calendar, and it doesn’t work. I can get my calendar feed using a test php file with no problems, and of course the lite version worked. What do I need to do to fix this, as I really need this functionality to be working.

https://wordpress.org/plugins/all-in-one-event-calendar/