Like the good cooks above had suggested.A cooker and a therm are just a couple of tools and don't make us cooks any more than a bowling ball makes us a bowler.
It is common to try to add all recipes/techniques together to make the "perfect" dish on our first try.
These cooks often suggest the KISS technique,take careful notes,and change ONE thing at a time..
Yes, a CS is wonderful,yes- you will gradually learn to use it to suit YOUR needs/tastes.
Yes,that is normal.
Just like that bowler.
Never seen pull OUT of the cooker before 190*?No,not if you are making PULLED pork.
If you wish tender SLICES, 185* could be fine.
Yes,if you are a commercial establishment that must speed the cook up for less labor,less shrinkage, higher yield and you will hack up with twin cleavers or drop in a "buffalo chopper" from Hobart- then 170* should be fine.
Is the butt previously frozen? Is it from a 700 lb, 20 year old sausage sow-rather than a 220 lb market hog?
Is it an 8-10 lb butt where 2 hrs/lb works out mathematically,or a 3 lb piece of butt that must still cook low and slow to break down collagen and render fat for 16 hrs to be pullable?
Are your temp probes checked and accurate? Is the cooking spot on the grate ACTUALLY at 225*?
Does your cooker really cook better at 235* than 225*?
Simple to answer these questions,isn't it?
The repeated attempts,the careful notes taken,gives the above cooks the EXPERIENCE to make their cookers work FOR them and makes them the fine cooks they have now become.
Relax,practice and they'll make you a fine cook, as well.