I've got some other options to scroll down your reports in QuickBooks Online (QBO), Lorna.
You can use the arrow keys on your keyboard or the Page Down key to scroll down reports without using the scroll bar. You can also try using the scroll wheel on your mouse if you have one.
I've added this resource to learn more about personalising your reports in QBO: Customise Reports.
Also, this article can help you export your data for future tasks: Export Reports, Lists, and More.
Let me know how else I can help you with reports by commenting below. I'm here to lend a helping hand. Keep safe always.