Commarker B4 20W Fiber - Unable to lower power to zero

Allow me to quote you:

This quote has never made more sense.
It will go down in the annals of history!

I recall there was a bug for certain boards in grayscale mode in an earlier version of Lightburn, but it seems that was BSL specific. Can you run the test file posted here: Photo engraving on stainless steel in grayscale - #18 by NicholasL and show the results? Or post pictures of your settings, a file you are trying to engrave and a photo of the results? (or both!)

I used the settings you had and here’s the result.

I did a second burn using the settings I have. These shades were determined by speed and frequency.

I’m going to say that this is a limitation of my laser and leave it at that.