Custom message missing in Response Headers from a Post/Create request

[#1]

There is a property I need from the response headers in a SAPUI5 app, which is "sap-message". It carries some information after a create request on the model in the SAPUI5 front-end.
On the app with a service pointing to Dev, I do get this property ("sap-message") attached to the headers, as you can see in the below.

The problem is that on the app that is on QA this property is not there, not just that it doesn't have a value, it is totally absent. What might be the cause of this and how to fix it?

Any help with greatly be appreciated.