There are several feeds that the site has trouble fetching, because requests fail with “Can't connect to domain.” But I can access them fine in my browser. I'm not sure what causes this or how to get around it. Any ideas?

Examples:
https://brendandawes.com/blog/feed
https://www.eastlondonlines.co.uk/feed/
https://www.benovermyer.com/atom.xml

@OohDirectory can you hit them with curl from the machine the site is running on?
@jmason I should have thought of that - no, it doesn't work from the server using curl.