That is some great looking pulled pork.
Each piece of meat is different when it comes to the stall. It is all dependant on how much connective tissue is inside of the meat that needs to break down.
There are several ways to combat the dreaded stall.
1. Cook at a higher temperature. at 215-230 degrees you are going to be going really slow. Also if you were at 215-230 degrees on the dome thermometer you were probably cooking anywhere between 185-200 degrees at the grate temperature which could be the cause of your long cook.
2. After your butt gets to the color you want, wrap it in foil or butchers paper. This will help you get through the dread stall as the meat will now braise and heat is retained in the meat.
I would recommend getting a thermostat or temperature probe that you can put down on the cooking grates so you know 100% what temperature your meat is cooking at. Also the myth that only good bbq comes at cooking at 225 degrees is just that a myth. Try taking your cooking temperature up to 250-275 or even higher. You will get the same great results.
If you want to get even more daring start doing hot and fast cooks 300+ degrees. The hot and fast cooks do need a long resting time however so the meat is able to relax and come tender after shrinking down so fast from cooking at a high temperature.
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