Menu headers don't highlight on hover with Wacom tablets

Using a mouse, when you hover the menus headers (File, Edit, View, etc.), they highlight, as excepted (see menu-highlight-with-mouse.gif)

Using a Wacom tablet, they don't (see menu-highlight-with-wacom.gif).

Expected behavior: using a Wacom tablet, it should behave like with the mouse. Importantly, when one menu is already opened, then not auto-opening neighbor menus on hovering is quite an annoying usability issue: it makes finding an action quite difficult when you don't remember in which menu it is.

I reproduced this both on Kubuntu 18.04 and Windows 10, both in my own apps and in pre-built Qt Creator. I assume there's no problem on macOS since the menubar is native.

In all non-Qt-based apps that I tried, the behavior with the Wacom tablet is the same as with the mouse, that is, menu highlights on hover, as expected. So this seems definitely a quirk of Qt.