I don't understand why I'm suddenly getting extremely uneven and bitter tasting cooks on my 008 (last two butts). I'm using 1 normal size chunk and one tiny chunk of hickory at 225. On a 7.5 pound bone-in pork shoulder, cooked at ~90 minutes per pound the temp under the bone will be 205 (butter feeling with thermo), but above the bone will be ~180 and the bone won't budge. I let it go a little while longer and the bottom meat continues to rise in temp but the upper portion is still in the stall. Got frustrated, pulled it off, wrapped it in foil and towels, let it rest 2+ hours and and both temps came up a little bit but there was still a large difference. Beneath the bone pulled nicely but the top of the shoulder was stringy, dry and smoke bitter. I ended up throwing it out and will try again. I haven't had these problems before so I don't know if it was just a bad butt, bad wood, or operator error. Any tips would be helpful. Thanks in advance.