What is the orientation of that photo? Are the scan lines parallel to the baseline of the letters or perpendicular to it? What do the letters look like in the LightBurn workspace and Preview?
Run this test pattern on cardboard at a high speed / low power combination just marking the surface:
The result should look exactly like the layout in the LightBurn workspace; if it does not, then there are likely mechanical problems.
What did the mechanical backlash look like before you applied the Ruida controller’s “correction”?
That correction does not eliminate the backlash, but attempts to hide it in places where you won’t see it. That generally fails in puzzling ways; the only real fix requires eliminating the mechanical backlash at the source.
