Feed Items from The Events Calendar Feed not displaying on frontend.

I have several feeds sources that fetch from The Event Calendar RSS feeds. The feeds have been verified through W3C’s RSS checker. Also the feed items are getting populated in the WP RSS Aggregator plugin. However, when the shortcode is added to a page, it displays “No feed items found.”

I tried with traditional WordPress RSS feeds and they work fine. When I compare these event feeds with traditional WP feeds, they have the same structure.

I’m not sure what is tripping WP RSS Aggregator up about these feed items.

Any help is appreciated, thank you.