Why doesn't OracleDataAdapter.Fill work with this Natural Join SQL Statement

Question

I am having trouble getting certain SQL statements containing Natural Joins to work with OracleDataAdapter.Fill(). I am using Oracle.ManagedDataAccess 4.121.1.0.

To illustrate this, review the following valid SQL statements. All work properly in a SQL editor. However, the last one does not work via ODP.NET when I use the OracleDataAdaper.Fill method. I have not had any trouble using a OracleDataReader with any of these statements.

Works with OracleDataAdapter.Fill

SELECT *
  FROM Operation_Settings, Settings
 WHERE     Settings.Setting_ID = Operation_Settings.Setting_ID

Works with OracleDataAdapter.Fill

SELECT * FROM (Operation_Settings NATURAL JOIN Settings)

Does Not work with OracleDataAdapter.Fill

SELECT * FROM Operation_Settings NATURAL JOIN Settings

Exception Message:

Oracle.ManagedDataAccess.Client.OracleException: ORA-00942: table or view does not exist

Data Access Layer function performing DB lookup and fetch

Public Function GetQueryResults(parameters As Dictionary(Of String, Object), query As String, connectionString As String) As DataTable

    Using table As New DataTable

        Using conn As New OracleConnection(connectionString)

            Using cmd = CreateOracleCommand(query, parameters, conn)

                Using adapter As New OracleDataAdapter(cmd)

                    adapter.Fill(table)

                    Return table

                End Using ' adapter
            End Using ' cmd
        End Using ' conn
    End Using ' table

End Function

I am open to any ideas and will upload any additional info you require.