I can subscribe to the RSS feeds for the Google Alerts in Feedly but not in the podcatcher. Why is this

Here are all of the settings I have chosen for all of my Google Alerts:
sources: automatic
how often: as it happens
language: English
region: any region
how many: only the best results
deliver to: RSS feed

My Feedly client displays text items from my Google Alerts feeds, but my podcatcher–Grover Pro, an app from the Windows Store, running on Windows 10 Pro–gives me the following error message when I try to subscribe to those same feeds: "can't subscribe to feed. This is not a valid feed." I also tried another podcatcher–"Podcasts (beta)", published by David Catuhe, available in the Windows Store–and was not able to subscribe to the feed in that app either.

I would like to be able to read text items from my Google Alerts feeds on Feedly.com or in my third-party Feedly client, and watch video from those same feeds in my podcatcher.