Execute multiple queries in parallel with Dapper

I trying to execute three similar SQL queries in parallel using Dapper and stored procedures to get three similar results after all queries are completed.

Here is my code:

public class SomeReport
{
    private static readonly string ConnectionString = ConfigurationManager.ConnectionStrings["SomeContext"].ToString();
    public ReportStatus ReportStatus { get; set; }
    public long NetworkServerTime { get; set; }
    public string ReportLastErrorMessage { get; set; }

    public RowSet[] FirstRowSet { get; set; }
    public RowSet[] SecondRowSet { get; set; }
    public RowSet[] ThirdRowSet { get; set; }

    public Report()
    {
        NetworkServerTime = 0;
        ReportStatus = ReportStatus.NotCreated;
    }


    public async Task GetReportDataAsync(ReportParameters parameters)
    {
        DynamicParameters requestParameters = new DynamicParameters();
        requestParameters.Add("@sinceDateFilter", parameters.SinceDate?.Date, DbType.DateTime);
        requestParameters.Add("@untilDateFilter", parameters.UntilDate?.Date, DbType.DateTime);
        requestParameters.Add("@countryId", parameters.CountryId, DbType.Int32);

        ReportLastErrorMessage = null;

        Task allTasks = null;
        var stopWatch = new Stopwatch();

        try
        {
            var firstTask = GetRows("[dbo].[GET_Report_FirstRowSet]", requestParameters);
            var secondTask =
                GetRows("[dbo].[GET_Report_SecondRowSet]", requestParameters);
            var thirdTask =
                GetRows("[dbo].[GET_Report_ThirdRowSet]", requestParameters);

            allTasks = Task.WhenAll(firstTask, secondTask, thirdTask);

            FirstRowSet = await firstTask;
            SecondRowSet = await secondTask;
            ThirdRowSet = await thirdTask;
        }
        catch (Exception ex)
        {
            ReportStatus = ReportStatus.Error;
            ReportLastErrorMessage = allTasks?.Exception?.InnerExceptions.Last().Message;
        }
        finally
        {
            if (ReportStatus != ReportStatus.Error)
            {
                ReportStatus = ReportStatus.Success;
                NetworkServerTime = stopWatch.ElapsedMilliseconds;
            }

        }
        stopWatch.Reset();
    }

    private async Task<RowSet[]> GetRows(string procName, DynamicParameters parameters)
    {
        using (var conn = new SqlConnection(ConnectionString))
        {
            RowSet[] rowsSet;

            try
            {
                var sqlString = string.Concat(procName, " @sinceDateFilter, @untilDateFilter, @countryId");
                var query = await conn.QueryAsync<RowSet>(sqlString, parameters, commandTimeout: 500);
                rowsSet = query.ToArray();
            }
            catch (SqlException sqlEx)
            {
                rowsSet = new RowSet[0];
                throw;
            }

            return rowsSet;
        }
    }
}

But when I launch the debugger and SQL Server Profiler, I see that the queries are executed sequentially when creating the tasks corresponding to them.

How can I make queries start running at the same time and run in parallel?