Hi Michal,
Thank you for contacting Syncfusion support
We have analyzed your reported issue and attachment, but we are unable to reproduce the reported issue in our end. We have prepared the sample with details you have shared with us and we request you to revert us by modifying the sample based on your application along with the replication procedure. This would be helpful for us to serve you better.
In our sample when scrolling the Gantt container, the Gantt rows are rendering properly without any issues in Internet Explorer and Microsoft Edge browsers.
We have prepared the sample for your reference, please find the sample from below link
Please let us know if you require further assistance on this.
Regards,
John R
