LoopBack request failed

Suddenly we’re suddenly facing issues with the latest EDD release. I have tried to replicate the issue on a couple of servers.

The loopback request to your site failed, this means features relying on them are not currently working as expected.
Error: cURL error 28: Operation timed out after 10001 milliseconds with 0 bytes received (http_request_failed)

We’re using the Software licensing extension & this issue is stopping the users to activate and download updates from our server.