Hi Nivedita,
We regret for the inconvenience caused.
We are analyzed this issue with Gantt control, we are found that it is due to performance delay of scrollbar rendering when resize the splitter in IE. Hence, we reported to the concern team and they are working on it, we will include this fix in the our upcoming Volume 2 SP1 release which is available at the end of May, 2017.
Please let us know if you need any other assistance.
Regards,
Jayakumar D