Ahh, but it’s not. As a woodworker, you understand dimensions and distances. You asked the machine to cut a 18x24 rectangle, but you didn’t know where the machine was measuring from. Using Easel, you programmed it to start at the lower (front) left corner, but did you set your xy zero there before you started the cut?
The machine will do what you tell it to do, but you don’t know what you’re telling it to do.
Don’t start by cutting a rectangle.
Start by homing the machine. Do you know what that does?
I know a guy.