C# - weird issue with setting value via reflection

I've got this helper method SetProperty that sets the property of an object via reflection. Below, is 2 scenarios where I use that method. The first method CreateInstance works just fine, but the second method Insert doesn't work.

In the 2nd method, the property set on the object is lost as soon as the method SetProperty returns. I've debugged it via visual studio. The object has the property set uptill the last closing curly braces. Then as control is returned to the caller Insert, the Property value is lost.

Method that sets properties

[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void SetProperty(object destination, string propertyName, object value)
{
    var type = destination.GetType();
    var property = type.GetProperty(propertyName);
    var convertedVal = Convert(value, property.PropertyType);

    property.SetValue(destination, convertedVal);
}

The SetProperty method works fine in this method

public static T CreateInstance<T>(SqlDataReader row, IEnumerable<CLASS> columns)
{
    var type = typeof(T);
    var obj = Activator.CreateInstance(type, true);

    foreach (var column in columns)
    {
        SetProperty(obj, column.BackingPropertyName, column.Name);
    }

    return (T)obj;
}

The SetProperty method doesn't work in this method

public T Insert<T>(T obj, string table = null)
{
    // CODE CHUNK
    using (var conn = new SqlConnection(this.ConnectionString))
    {
        conn.Open();

        using (var cmd = new SqlCommand(query.ToString(), conn))
        {
            // CODE CHUNK

            var autoGeneratedValue = cmd.ExecuteScalar();

            if (temp.AutoGeneratedColumn != null)
            {
                ReflectionHelper.SetProperty(
                    obj,
                    temp.AutoGeneratedColumn.BackingPropertyName,
                    autoGeneratedValue
                );
            }
        }
    }

    return obj;
}