The tutorial to add events to RSS feeds (https://theeventscalendar.com/how-to-add-events-to-your-rss-feed/) could use one improvement. Posting to the forum because comments on that page are closed.
As written, the code to add event date to your RSS feed will add a start date to event posts (as desired), but also adds a start date to regular posts, which makes no sense. Clearly tribe_get_start_date() returns now when it is not an event post.
I suggest you modify the tutorial and encapsulate the with the conditional “if (tribe_is_event())”. That should remove the nonsensical event dates on regular posts