Does the RSS feed from the Events plugin do anything?
I get this rather lean output:
<?xml version="1.0" encoding="UTF-8" ?>
<rss version="2.0" xmlns:discourse="http://www.discourse.org/" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:dc="http://purl.org/dc/elements/1.1/">
<channel>
<title>eHealth Forum Events</title>
<link>https://forum.hinz.org.nz/calendar</link>
<description>Events</description>
<language>en-GB</language>
</channel>
</rss>