You cooked a 2-3 lb butt for nearly 12 hours at 225? I think that might have been your problem.
You will need to nail some things down, starting with the temperature inside your pit. Once you know that is correct, nail down the temperature readings from the probe.
A guideline for pork butt is 1.5 hours per pound @225. It shortens the higher the temp of your pit. That butt shouldn't have gone on longer than 4, maybe 5 hours.
Dbl Bbl Smoker, UDS, ECB, Char-Broil gas grill & charcoal grills, SJ - Certified Moink Baller