I found this :

mouse on north edge --> move north

mouse on the North-East edge and then it will go NE

mouse on E edge then it goes W

mouse on W and it does nothing

mouse on south won't do anything unless you put the mouse in the center (between the two white panels)

Same here with the wonky scrolling.

For me the Western edge of the screen has never done anything, except for the NW corner which has the effect of scrolling to the SW. The Southern edge sometimes works when I start the game up, but after a minute or two it also become unresponsive. Aside from the NW corner, none of the other corners do anything scolling wise.