Azure QnA maker fails to create a knowledge base by raising ExtractionFailure error code

We have the following code snippet that is supposed to create a knowledge base:

        var createKbDto = new CreateKbDTO
        {
            Name = request.Name,
            QnaList = new List<QnADTO>(),
            Urls = new List<string>
            {
                "https://function.mydomainname.xyz.com/api/job/Facade/777/43D672205C3106BE3273C60FE423C932"
                //"https://myowndomainname.xyz.com/jobs/281735/something"
            }
        };

        var createKb = await client.Knowledgebase.CreateAsync(createKbDto);
        var createdOp = await MonitorOperationAsync(client, createKb);
        return GetKbId(createdOp);

The second fictitious URL in the Urls list above is picked up successfully and Azure knowledgebase is created. However, feeding the first URL causes the following error message to raise:

Unsupported / Invalid url(s). Failed to extract Q&A from the source

I cannot make any sense why the 2nd Url works well for the QnA maker SDK but not the first one. When I plug in the first URL in a web browser or POSTMAN, I can easily view the response in pure text on the browser or POSTMAN. Please note that the technology behind the first URL is an Azure Http-triggered function.

Any explanation or point for this problem?