the rich results report previously supported only job posting and recipe markup, but now, it supports event markup as well. One of the first to notice this and post about it on Twitter was Aaron Bradley.
It seems that, with this update, Google is sending out new notifications to sites verified in Google Search Console that have issues with their event markup.
If you are posting about events on your website, host conferences, and the like, you can amplify your search result snippet with event markup. If you end up marking up your content incorrectly, Google can proactively notify you of issues. This way, you can fix them at a quicker pace.
If you have events on your website and use the markup, you can access this report within the Google Search Console enhancements section. Scroll to the bottom section of the Search Console and look under the “enhancements” section. If you see Rich results, you may see event markup fixes for you.