Invisible scroll bars are a source of constant annoyance. And it sometimes takes me several attempts to move a window, because of all the various clickable things without visible boundaries. Frustrating.
On GNU/Linux run this command, it will fix it for all the GTK based desktops, such as XFCE, Gnome and Mate:
gsettings set org.gnome.desktop.interface overlay-scrolling false
On GNU/Linux run this command, it will fix it for all the GTK based desktops, such as XFCE, Gnome and Mate:
Under Mac you might have a similar Cocoa setting or whatever is called (nsproperties?) with "defaults write".