Not sure if this is an Atomstack issue, or Lightburn.
When framing anything, the laser is slow to turn on with my S10. It comes on about 3/4 of the way through the first (bottom) movement of the framing.
In the Move Window what Speed is set there and what are the units by which the speed is measured? You will need to set this below the maximum speed allowed by the engraver.
It was set at 6000mm/min, well within the spec of my 10W diode laser. I turned it down to 4000. It’s still a delayed start but with the frame scan that bit slower, at least I now get to see some of the bottom scanned!
Specifications and settings can be different.
At your convenience, open the Console window in LightBurn and type the following:
$$
then press enter.
From that report copy (and paste) the part that says what $110 and $111 are equal to. That’ll tell us if the dimming is caused by the motion planner or not.
I get:
$110=6000.000
$111=6000.000