i too have had this problem a few times with my elite. even on overnighters with pork butt. sometimes the chunks will be completely ash in the morning when i check, but sometimes the wood chunks are still whole, but all black.
i put the chunks at the front too. though i put them where they arent covering one of the holes in the wood box.
im betting its the wood though because it does turn to ash more often than not. im using cookshack wood chunks. thinking i should leave the rest outside in the hot summer sun for a day or two.