The way you can check if your RSS Feeds have been set up correctly is by going to the Discover channel, and clicking "Manage Sources":
Under 'Status' there will be a tick if the RSS Feed is set up correctly:
If the RSS feed is not set up correctly, there will be an 'x' under 'Status'.
To correct the RSS feed, try the following steps:
Check that the RSS feed is still active.
Make sure that the URL is a link to the website's RSS feed and not just a link to the website.
If the RSS feed is still not working, please try deleting it and importing it again.