Desktop Icons Tooltips - Strange Behavior

I've observed this on our Dell and HP pcs. If I open a file, folder or shortcut on the desktop, then close and go back to the desktop, a tooltip will not appear on any icon when I hover the mouse pointer over it. But if I then click anywhere on the desktop and hover once again over any icon, the tooltip now appears. Presumably this is all by design. But why?

I'm on 25h2 and that is the way it works for me too. Who knows why MS does what they do?

It's to do with Focus surely? Switching Focus back to the desktop is not automatic after you close an app so you click on the desktop to tell Windows to switch focus to it. Only then will it follow the cursor and register that it is hovering over an icon and display tips.
Yes, I believe it is by design since Windows is not intelligent enough to know where you want to shift the focus to next. You have to tell it.