Download an example of dhtmlxGantt with ASP.NET MVC chart on the official website. When the task is modified after successful operation, the SortOrder becomes 0.
Hello,
The SortOrder value depends on the task position.
Gantt is only a client-side application. If you reorder tasks and save them in the database, you need a solution to save the order of tasks. Otherwise, Gantt will load tasks with the default order(according to the order in the table).
On the following screenshot, you can see the different SortOrder values and the task position in the grid: