Smoked a butt on the egg last night. I've done a fair amount of these over the last two years but I had something happen last night that has me stumped.

8 lb butt
BGE lump
225 Temp

Set the temp on the egg around 9:00 pm and after making sure the temp was stable I put the butt on. Went to bed about 12:30 and temp was holding steady as usual. Woke up at 6:00 to let the dogs out and check on the meat and my temp is basically less than 100.. No vents were closed more than they should be and there was still plenty of charcoal and lump in the egg. Started the fire back up again to finish the butt and temp has held steady all day. No idea what happened or why.

This ever happen to any of you guys with BGE's?