I am running sikuli on a linux machine with two screens (1920x1080 (x=0 , y=0) and 2560x1600(x=1920,y=0). When I move to x=4479, it only goes to about 1/4 of the way across the second screen when I expect it to be at the screen's edge. Why?

I am running Sikuli on a Linux Machine with two screens (1920x1080 (x=0 , y=0) and 2560x1600(x=1920,y=0). Screen(0) and Screen(1) return what I expect based on the known screen information. The max x position possible should be 4479 (1920+2560) and y will be 1599. If I have Sikuli try to click(Region(4479,1559), it should click the bottom right corner of the 2560x1600 screen. It does click at the bottom of the screen (so the y-coordinate works as expected), however the x position clicked is somewhere about 1/4 of the way (maybe less) into the 2560x1600 screen. It is also most as if the x position is 1/2 of what it should be. I have no idea why this is happening. If I try to increase the x position to 5000 (or anything above 4480), I get an error saying I'm going beyond the bounds of the screen, which I would expect happen. It seems like the x coordinate is simply not matching the the screen x coordinate. Any idea what would cause this and/or how to fix it?