WP HTTP Error: cURL error 28

I'm getting the error:

WP HTTP Error: cURL error 28: Operation timed out after 10000 milliseconds with 0 bytes received.

I checked the RSS URL and it loads okays. But it does load a little longer, probably- 3-5 secs.

Note: it did use to work. But I had to deactivate the plugin for a few days. And when I turned it back on, it stopped working.
Thinking it is server issue, I moved the site to a different hosting provider and I'm still having the same issue.