Yet another UDS build!! But is mine any different?

First cook on the Big Ugly. Two butts, drum held temp well. Only problem was I used royal oak lump and it burned out really quick. I had it shut down on both ends but it still only lasted about 7-8 hours. Friday I did a test burn with Kingsford Bricks and it held 250 for 14+ hours. Anyone else have this problem???