Repeated doctype and head on event pages

On event pages I’m getting an entire document (doctype, head, etc…) printed inside of the content area of the page. It appears the events calendar plugin is outputting a full page render. I thought at first that my theme might somehow be repeating the get_header() call but the doctype on the inner document is different, so that isn’t it.

Any ideas? I’ve got a malformed document on all of the pages that events calendar outputs.

https://www.ads-software.com/plugins/the-events-calendar/