I encountered this issue last week and properly cleaned everything before running another test. BUT:
The glowforge is still not cutting properly. The cut line is broken in some places. Same goes for Scoring - it is pretty light, even though the Gift of Good Measure has the scoring settings on draft (which, in my experience, scores deeper). The engraving works just fine, though. I used proofgrade draftboard for my personal project (a few puzzles for my toddlers to color), and the Gift of Good Measure. All designs were cut/ engraved/ scored on proofgrade settings. Not only is the cut line broken, but the material isn’t even cut the whol eway through. You can’t even make out the cut marks on the back of the material.
My glowforge plus is in our basement. Is it too cold? I haven’t had any problems during summer and cut acrylic many times.