Newbie requires help getting started cutting

I just pruchased an AtomStack X20 Pro laser machine and starting to play around with Lightburn to create some Acrylic labels. The sheets I purchased are 3mm 2-color (red upper layer and white).
The text came out fine except not entirely white (so I think I need a bit more power to get deeper cut through red layer to the whie - this is ok). The main problem is I have a ragged (burred) edge on the underside of the cut. Is this cause by power too high or too slow speed? What is the workflow to set up the speeds and power for good text engraving and also the cut out of the shape ? Thanks