I have a page built with the Right Side Column template. The page itself has content that requires the user to scroll down to see it all, and so does the right side column.
On Firefox, as the user scrolls down the page the right side column also eventually scrolls so that all its content can be seen. However, on Chrome the sidebar doesn't scroll so you can never see the content that is initially off the page.
The behaviour has changed since APEX 20.1 when the right sidebar would have a scrollbar if its contents were not all visible.
I have created a demo of this issue here:
https://apex.oracle.com/pls/apex/tonyng/r/apex-21-19/right-sidebar-scrolling
(User/password: demo/demo)
The main page and sidebar contain the same report with 30 rows displayed.