Dataset has no values even though procedure is returning proper value

Question

I have a procedure where I am using OPENJSON to display the Json string as key value pairs. When I execute the procedure, it is returning the expected value bu in controller, the dataset is empty. It only shows the table headers - key, value, type. No data at all. When I use a different very similar procedure, it it seems to work fine. Not sure what is happening. Please help! Thanks in advance!

This is my procedure:

CREATE PROCEDURE [dbo].[PROC_NH_Journal_Tab1Data]

@EnterpriseId nvarchar,
@exactgroup nvarchar
AS

declare @json nvarchar(max)
    set @json=(select Tab2Json from tbl_NH_T_JournalDataPost where 
    EnterpriseId=@EnterpriseId and GroupName = @exactgroup)


SELECT * FROM  
OPENJSON ( @json )
Return 0

And here is my action:

public JsonResult GetAnswersFortab1(string exact)
{
        string JSONresult = string.Empty;
        string EnterpriseId = "User";
        try
        {
            SqlConnection sqlcon = new SqlConnection(con);
            SqlCommand cmd = new SqlCommand("[PROC_NH_Journal_Tab1Data]", sqlcon);
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddWithValue("@EnterpriseId", EnterpriseId);
            cmd.Parameters.AddWithValue("@exactgroup", exact);
            sqlcon.Open();
            SqlDataAdapter adapter = new SqlDataAdapter();
            adapter.SelectCommand = cmd;

            DataSet data;
            data = new DataSet();
            adapter.Fill(data, "Table2");
            DataTable dt1 = data.Tables[0];
            ViewBag.getJson = dt1;
        }

The procedure when executed, gives a table with key, value pairs. But when I debug,in action, the 'data' is an empty table in 'DataSetVisualizer'. Empty table only with headers(key,value,type).No data is present. Here is my Print @json from the procedure

key       value    type
emoji2      2        1
check2      on       1
check5      on       1
check7      on       1
hiddentext  weds     1