upstreamDatasources missing for some of the workbooks while using the metadata-api (GraphQL)

[deepjyotiroy079]

Describe the bug
I'm using a GraphQL query to fetch workbook related information but it seems the query misses out some of the data sources, all of which is still visible on the tableau cloud data source section for the dashboard.

Versions
Details of your environment, including:

• Tableau Server version: 3.20
• Python version: 3.10
• TSC library version: 0.25

I'm using the below query:

{
    workbooks {
        name
        projectName
        projectVizportalUrlId
        owner {
            id
            name
        }
        uri
        upstreamDatasources {
            name
            updatedAt
            extractLastRefreshTime
            # extractLastUpdateTime
        }
    }
}

Results
Does not display any upstreamDatasources, but the same exists.