Are you using the laser module in gSender? If so, check what the “laser power”/“max power” is set to. I don’t use this setting in gS, but in my installation the max power is set to 100. I believe that is the default. If your installation says the same thing and you have set sMax in LB to 255, you have a mismatch. Your gcode will be written assuming $30 is set to 255 since that is what you set in LB. However, your actual $30 setting will be 100.
If you are setting Smax to the same value as the max power in gSender, ignore all this.
@Ssuthe5567 If Edge has the same settings as gS, there should be no performance difference. Post your gcode if you like and I and others can see if anything jumps out. If I were you, since you designed this in LB, I would simply cut it in LB. If that works, then you know the issue is something going on between LB and gS.
Not sure if this will help but I would not use that much step down each pass. What I do for a step down is divide the thickness of the material by the number of passes to calculate the Z step down. So 0.375mm in your stated case of 3mm material at 8 passes. That should help to maintain the proper focal length from the material. Just a thought and it maybe it is not what is causing your problem but the way I see it on the eighth pass you are at least 5mm out of focus.