Undocked window sizing handle hot area inverted

Using Ubuntu 18.04, almost anything on default configuration, Unity 2019.2.6f1.
Undocked windows appear to have their draggable sizing handle area inverted when compared to other OS/application windows meaning those seem to have a margin/area slightly larger than the window for resizing, but unity's child windows seem to be overlapping/turning that interaction-area inwards which makes it partially obstruct scrollbars and system-buttons (the close-button in particular) that are near the edge and thus hard to click properly. I often find myself accidentally resizing the window instead of scolling.
Is that a feature on my system or to be expected?

 

Just a little followup, it looks like this only happens with gnome (maybe even just for me), but now under kde plasma it works fine/as expected.

 

I see what you're saying. Weird. Can you go to "Help > Report a Bug" and log a bug on this issue so we can track it?