I don’t use MAC OS myself but many other Users I know do, and I am not sure if this is new in Catalina OS, the latest update ?, but I have had to show People numerous times in the last month or two, how to both turn Scrollbars and the Mouse Right Click Buttons on, some didn't even realize their Mice had a Right Click option.   1.     MAC OS  seems to have its Scrollbars Turned Off by Default, so they aren’t seen in Chief either after Enabling them in View > Scrollbars