Elements don't scale correctly with Windows UI scaling

I have Windows 11 set to a UI scaling of 175% using the System -> Display -> Scale & layout setting. This leads to all tooltips and menu items in my Qt programs being comically oversized. I'm attaching three screenshots of a simple test, a window with a label and a tooltip at 100%, 150% and 175% UI scaling. As you can see, the tooltip becomes becomes too large at higher scalings.

The helper programs shipped with Qt actually have the same problem - see the screenshot of assistant.exe.