I would suggest not temp probing ribs... Your problem may be that the probe is either protruding somewhere and is reading the heat in the cooking chamber.
What type of ribs are they? Baby backs, St. Louis, or Spares? I'd keep them cooking as they are for another hour if BBs and another 2 hours if Spares, and then put them in foil (at that point it would be 2 or 3 hrs into the cook). Keep them in foil for another 2 hours and continue to check to see if the meat pulls back from the bones a little and check to see how pliable and tender the meat is. Once you are comfortable with the tenderness of the meat, you can put them back into the smoker bare and let the bark / outside of the meat firm back up. At that point you can glaze on some sauce.
You'll know when the ribs are done when they feel like you can pull the meat off the bone.
Also, even though I said check the meat for tenderness, try not to open the door as much as you can. This will make you lose heat and will prolong the cooking time.
Lastly, my suggestion for next time is to get a better thermometer for your smoker to know for sure what temperature you are cooking at. The stock therms on smokers are usually not that reliable. A good one to get is the electronic maverick therm, which has both a cooking chamber probe and a meat probe.