cURL error 28 intext:”Plugin: WP Fastest Cache”

I am attempting to reconnect a website to the Stackpath CDN using WP Fastest Cache. When I enter the CDN and source URLs into the proper location and click the Next button, I’m getting a cURL error 28 error, with the message that “Operation timed out after 20001 milliseconds with 0 bytes received.

Note that since I am using the plugin to send all content to the CDN, I did not update DNS with A or CNAME records to Stackpath.

I’d appreciate knowing what the issue is and how to fix it. Thanks.