Because oracle does not return all the records when I do a select from c#

I'm doing an insert then a select with oracleclient in c#. The direct query to the database returns me this:

However, when I do the select from a windows forms app, it returns the following:

The query is not being made from sql because the tables have different names and in the case of sql it brings the data well:

As you can see, it doesn't bring me the rows that have the null date in the database, why does this happen? The code is this:

private async Task cargar(string c)
    {
        string sentencia = "";

        DataTable dt=new DataTable();

        switch (c)
        {
            case "SQL":
                sentencia = "select * from pushes";

                using (var con = new SqlConnection("Server=zzzz;Initial Catalog=zz;User Id=zzz;Password=zzzz;"))
                {
                    await con.OpenAsync();


                        SqlDataAdapter adapt = new SqlDataAdapter(sentencia,con);

                        adapt.Fill(dt);


                    dataGridView1.DataSource = dt;
                }
                break;
            case "ORACLE":

                sentencia = "select * from departamentos";

                List<departamentos> depas = new List<departamentos>();

                List<object> objetos = new List<object>();

                using (var con = new OracleConnection("Data Source=zzzzz/test;User Id=zzzz;Password=zz;"))
                {
                    await con.OpenAsync();

                    OracleDataAdapter adapt = new OracleDataAdapter(sentencia,con);


                    adapt.Fill(dt);


                }

                dataGridView1.DataSource = dt;
                break;
            default:
                break;
        }
    }

To do the insert I use this code:

case "ORACLE":

                 sentencia = "INSERT INTO departamentos (depto_id,nombre,localidad,fecha_creacion)" +
                " VALUES" +
                "(:depto,:nombre,:local,:fecha)";

                using (var con = new OracleConnection("Data Source=localhost:1521/test;User Id=system;Password=sa;"))
                {
                    await con.OpenAsync();

                    using (var comando = new OracleCommand(sentencia, con))
                    {

                        comando.Parameters.Add("depto", 2);
                        comando.Parameters.Add("nombre", "oracle");
                        comando.Parameters.Add("local", "oracle");

                        comando.Parameters.Add("fecha", DateTime.Now);

                        var reader = await comando.ExecuteReaderAsync();


                    }
                }

                await cargar(comboBox1.Text);