FrankenForge ... a Glowforge salvage project

So here’s a laser power question …
While verifying the stepper motor settings with the 100mm square test suddenly the laser needs a significant bump in power to cut the same material it was just cutting.
Or to say it a different way …
65# card stock was taking 11% power and then after changing the stepper number in the firmware the power needs a bump to 30% power to do the same job.
Cut speed is consistent, unchanged.
Any ideas ?

What about PWM tuning ?
Saw this page in the Cohesion3d knowledgebase.
Is this a thing ?

Thanks