This is an expected behavior for lettering while using this setting at that level of "zoom".
I see it as when you zoom a picture, it also has that effect.
I am afraid it is NOT expected behavior. many other windows, dialogs apps (even native to the OS) render well, but this Device Manager is particular does not.
The level of zoom is necessary with a High resolution display, where the recommended resolution is 3200 x 1800.