"The request has timed out" during certain hours

What is the name of the domain?

What is the error message?

The request has timed out.

What is the issue you’re encountering

One of our users is getting the “The request has timed out.” during specific hours of the day. Client complains that it is a problem of the application but no other user complains about it. Traceroute problems? SSL or do I need to change something in my origin server’s access rules?

What steps have you taken to resolve the issue?

None yet.

What feature, service or problem is this related to?

I don’t know

What are the steps to reproduce the issue?

Please check screenshot attached.

Screenshot of the error

Additional screenshot to help with context: