Hi Mark,
Thank you for contacting Syncfusion Support
We have observed the reported query and found that it relates to ScrollBar, the Microsoft component and not the Syncfusion controls. However, could you please explain whether you are involving any works related with any of our Syncfusion components. If so, please brief about your requirement or else please contact Microsoft for the Scrollbar related queries.
Regards,
Subburaj Pandian V