This appears to be a bug although it may be a symptom of something else.
When downloading box dieline SVG/DXF files some lines were consistently not cut:
When cut selected turned off the lines would be traced by the laser but the laser turned off
When individually selected the lines would be cut with cut selected
When all selected the lines would not be cut with cut selected
I tried selecting the lines and doing an 0.00mm outline so that LB created ‘new’ lines itself, same result.
Sample files attached for testing. I use an Ortur Aufero2 which is usually flawless for me. The missing lines for me are the ‘curved tab’ ones. LB Preview displays and plays them as if they would be cut (the head does move for them but the laser is off / at 0% power for them)
Try disabling “Constant Power Mode” and see if that makes a difference. If so, it’s likely a bug in the firmware for which I believe Ortur has a fix in later revisions.
Glad that worked. In general I’d advise against using “Constant Power Mode” in any case unless yo have a specific reason for doing so. Enabling will generally result in worse results with respect to overburning.