mouse moved wrong in second screen

[mostcute]

my robot version is

require github.com/go-vgo/robotgo v0.100.10

i want to move the mouse use the code like this

func main() {
    for i := 0; i < 100; i++ {
        time.Sleep(time.Second)
        fmt.Println(robotgo.GetMousePos())
        robotgo.MoveRelative(10, 2)
        fmt.Println(robotgo.GetMousePos())
    }
}

it works good in my first screen and the log is

428 595
438 597
438 597
448 599
448 599
458 601
458 601
468 603
468 603
478 605
478 605
488 607
488 607
498 609
498 609
508 611
508 611
518 613
518 613
528 615

it moved x=10 and y=20 per sec

but it seems work wrong on my second screen

the log is

-1888 375
-2532 255
-2532 255
-2961 175
-2961 175
-3247 122
-3247 122
-3438 86
-3438 86
-3565 62
-3565 62
-3650 46
-3650 46
-3707 36
-3707 36
-3745 29

it doesn't move x=10 any more, is this looks like a bug?