Feed Items or Posts Not Importing - Check the RSS Feed Permalinks
When choosing an RSS feed to use with WP RSS Aggregator make sure that it provides permalinks for all its feed items.
Most commonly, an import from a feed source would be run more than once during its life within WP RSS Aggregator. This means that in order to avoid importing the same feed items over and over again, WP RSS Aggregator would need some way to uniquely identify an item in your system.
The most reliable piece of data to do this job is the permalink, as it is what uniquely identifies a resource on the web. For this reason, the link is required to be present for all feed items within each and every RSS feed.
Here’s what that might look like: