At some point I was using multiple monitors. I don't remember all the details.
BUT what I do remember, I needed the monitors in order.
IE: left to right, 1,2,3
Also I needed to make sure monitor 1 had 0,0 .
IE:
monitor 1; x:0 y:0 to x:100 y:100
monitor 2: x101 y:0 to x:200 y:100
monitor 3: x201 y:0 to x:300 y:100
I think I had to set the primary monitor to monitor 1 as well.