I am afraid that the provided information is insufficient for us to determine exactly why the Gantt is not rendered correctly.
One possible reason could the that the Gantt's container has a very small size. To overcome this we would suggest calling the resize() method of the Gantt control's widget as shown in this forum thread: Dynamic resize of Gantt
If that does not help, we would like to ask you to prepare a very simplified sample runnable project
of your implementation and send it to us in an Official Support Ticket. Thus, we would be able to investigate locally and help you more efficiently.
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