Hi.
The events feed works rather like the first page of the upcoming events list: it starts with current/ongoing events (those that perhaps started at some date in the past but have not yet expired) and proceeds to show future events, up to the limit set by the number of posts to display per page.
If you compare your main events list to the content of the main events RSS feed you can see that this is indeed exactly what’s happening. So, everything in fact appears to be operating as expected.
Does that clarify things?