Building area is only 768 meters across 2 ways

Hi, I noticed when I started making my first coaster that my mouse cursor would only go 768 meters across the area, according to the website the building are is supposed to be 1500x1500x500 meters, seemed to be confused by this, I have standard version of NL2 not the pro version.

I'd assume that the mouse cursor can also go 768 meters the other way (negative 768 meters).