Hi Amine Le,
Thank you for sharing the code example!
With it I was able to reproduce the issue and unfortunately this is a bug for which I will add a work item and we will work to fix it as soon as we can.
However a temporary relief for this is in your case is to set the height so that you don’t need to scroll the Gantt Chart.
Please, do not hesitate to contact us if you have any additional questions.
Best regards,
Yavor Dashev
Smart UI Team