Why such different results between LaserGRBL & LightBurn?

With my 3018 Pro & 5.5 watt laser: In LaserGRBL I was getting a good burn with speed at 4000 and power at 30%. Using those same settings in LaserBurn results in only a faint image. Which leads me to believe there is some other setting controlling the overall power in LightBurn but I have not been able to find it. Can you see what I’m missing?

this, possibly?

To emphasize @moors7’s point: be certain you set LightBurn to use mm/min speed units, rather than anything else, because the same numeric value (“speed at 4000”) will produce vastly different speeds and, thus, results with in different units.

That looks helpful but my setting as discussed in this document appear to be OK.
I’ve used up all my 30 day free trial and have yet to successfully burn anything.

Yes, I am using the mm/min setting.

A mismatch between GRBL $30 and LightBurn S-value Max will do that:

If those match, then the rest of that Troubleshooting section has more suggestions.