Thanks for contacting Syncfusion support.
We have checked the reported issue at our end with latest source version, we unable to replicate this issue in our local sample.
Can you please share us the below details, which will be very helpful to provide solution.
- Is this issue occurs randomly or all time while running the sample.
- Source version you are using in your sample.
- Browser details with version.
1. Kindly, share us the video sample to replicate the issue and code snippets used to render Gantt Chart.