Specific examples are spacing, which is bigger on uwp; latency and animation speed; and of course, windowing.
In terminal settings, for example, the settings editor is limited to the terminal window, and the save buttons are aligned to corners.
That means, for example, if the window is too big, the buttons are going to be very far away - lots of mouse travels, it means also that the window sizing will not be ideal - look at settings in Mac apps - there's a popout panel which adapts in size.
If the window is small, things will be cramped. On low resolutions or smaller screens, things are too big and cramped. The save bar occupies a large emtpy space bar on the bottom.
On large screens, high res, it's comically huge and with mostly empty space. It's just stupid.
Is this specific enough?
I just saw in an issue about this your PM say you're following uwp guidelines. That's certainly a part of the problem.
It's the classic "Garbage in, garbage out".