Hi Julie, I checked my power settings immediately after the print and while the machine was still printing, it was set to 700 speed, 40 power, which normally gives me a nice smooth engraving. 2 other pieces on the same print also turned out like this, while the other 6 pieces etched normally, all of them were set to the same settings.
On the the 3 that look burned, it appears they started to etch normal but then in the same etch process, it started to just etch/burn the top masking paper