Some really good advice given.
I agree that your smoker temp is the most likely issue.
Wholeheartedly agree on at least a dual probe therm, or even better a four probe.
Inkbird advertises here and they run some great specials on their for probe therms one is in effect now for $45 on
Amazon.com.
I also recommend a handheld instant-read digital thermometer for testing IT in various spots and testing probe tenderness.
Upping the temp and/or wrapping in foil or paper would have worked well.
If you know your temps are good and your meat was 140° within four hours then you can just let it ride.
Technically you were in the food poisoning danger zone if you failed the 140°/4 hour rule.
But should be good if the meat was not pierced for tenderizers/seasonings.
Butcher paper braises too.
It just breathes little which keeps your bark from getting ruined and no need to reset it after unwrapping.