Rig keeps stopping during project, but the laser keeps burning

This is caused by a USB communication failure, usually caused by the junk USB cable included with the machine, or a power glitch common to higher power laser machines running from a slightly under-spec supply. The machine’s controller crashes and resets, leaving LightBurn unable to continue.

A higher quality USB cable with ferrite cores on each end seems to solve most of the problems. Although the cores themselves may not be relevant, they seem to be present on cables with overall better quality. Buying a recognizable brand name, rather than an Amazon / eBay seller using random consonants, seems to produce better results.