I caught the laser tracing over each vector twice. That takes twice as long, and adds extra charring and/or lost material.
You can see the double cutting without actually running the laser by changing the mode to Simulate Vector and then hitting Go. Watch the red dot and see if it’s doing the wrong thing, as it was for me.
What’s going on here? The problem, in my case anyway, was easily fixed once I figured it out. The object was set to have an Outline property of 0.5 points. That’s a skinny line, but it has a width. When CorelDraw prints a line like that to the laser, it encodes it twice, once for each edge of the line. This is very nearly invisible and undetectable on the Vector tab of Retina Engrave 3D, unless you run the simulation. The solution is to set the Outline property to Hairline. That makes each line have zero width, and so it only gets one pass of the laser. That’s probably what you want.