I too seem to be having somewhat of the same problem. I have my primary with monitors 1 and 2 with 1 being the main monitor and my secondary with monitor 3 and configured from left to right is 3 - 1 - 2 and am running windows 10. I have microsoft flight simulator X steam edition on my primary and am networking other programs on the secondary. when I run FSX and try to move my mouse to the secondary (monitor 3) which is located on the left it won't go. It hangs at the edge of my main monitor 1, but if I go to the right through monitor 2 and wrap around to monitor 3 it seems to work somewhat, although I do have to click on monitor 3 for the pointer to show up. It seems that FSX has to lose focus before the mouse behaves properly and sometimes it gets so totally confused that the pointer won't show at all. Would like to purchase this but I need it to work. Any Help?

Edit:

monitor 3 - 1920 X 1080, monitor 1 - 2580 X 1080, monitor 2 - 1920 X 1080