Adding "Editor's Picks" in Google News

We're trying to impliment the "Editor's Picks" feature of Google News. When I submit the rss feed, it is giving the error "Feed Errors: We could not crawl your feed; the URL may be blocked by robots.txt"

The URL we're using is: https://www.westerngazette.ca/search/?f=rss&sd=desc&l=25&t=article&nsa=eedition&fl=featured&altf=google_newsstand

... which I think is the correct way for Google News. Anything glaringly wrong with what I'm doing?

Google News "Editor's Picks" Documentation: https://support.google.com/news/publisher/answer/1407682

Edit: Googlebot-News is allowed in my robots.txt settings.