I have been using my glowforge for about 2 weeks, maybe 15 hours or so print time so far, so I doubt its a cleaning issue, but I will clean before my next print.
Unfortunately, that does not help me save the sheet of PG maple ply that was effectively ruined by this recent print. Draftboard works fine, because it doesnt have the thin veneer, and the top layer is cutting fine, but the back layer of veneer is having trouble at times. 3 separate pieces of PG maple ply have had the issue so far, the first time I did not take any pictures because I had only had the machine a day, and I didnt think of it. Also, the cut was so close to the back that it was able to be popped out with a little force, but still cleanly.
These past 2 were not so lucky, On one, they ripped the veneer as they came out, ruining the pieces. On the other, they cut was so weak and the pieces so thin that they were effectively just scored and could not be removed at all.
Also, my camera does not seem to be perfectly aligned from cut to cut, so if I try to run the same cut again, even if I do not move the wood at all, it cuts slightly askew, preventing an additional pass from helping. (I noticed this issue with the tracing function too, it will cut or engrave the correct image, but not directly on the trace, which seemed wrong, but I had hoped it was just a 1 time calibration issue, but the issue persists after multiple days of turning the machine off for the night and re calibrating the next time I use it.
Edit: Forgot to upload my pictures.