When you drag+drop the grabber for the new Network Details panel (See #46219) the mouse cursor doesn't follow the grabber.
It seems that the resize component is moving things in relation to the page, but the size of the panel is relative to the container that it's inside of.
Or maybe the height of something is invisibly expanding which causes the mouse to move further for the same dragdrop effect? Not sure.
Compare grabbing that, to drag+drop the of the page sections, in that case the mouse follows the grabber icon and everything is well
See also #46219