How to stop submenu scrolling?

[Jiawen]

Sub-menus in the Applications menu often require scrolling, as shown in the attached image. Other times, the sub-menus display full height, with all their contents. It appears related to how recently the sub-menu has been opened, and thus to how recently the sub-menu has been loaded into memory, but this machine is not lacking in memory and my sub-menus aren't that big, so the scrolling is an annoyance. How do I disable this scrolling?

Thanks!