Sounds like you smoked them at too high a temp & rendered fat. One of the master sausage makers on here - Nepas - posted this method for sticks that works great...
From Nepas
Here is my table for sticks. I use a Bradley smoker with a PID.
1. Start at 130* for 1 to 1.5 hours (no smoke or water in the pan) This gives the casings time to dry some.
2. 140* with smoke for 2 hours. I use my water pan here, keeps the casings from being to brittle during the heat PID programs.
3. 150* for 2.5 hours. Check IT of the sticks with
thermapen (from the top of the sticks) smoke opt
4. 160* for 2.5 hours, check IT again. You should see approx IT of 125-130 and may even see a stall time. smoke opt
5. 170* for 2.5-3 hours. Again check IT as you should be getting close.
6. If needed bump to 175* while checking IT. Your looking for an IT of the meat of 152*
6a. Try not to exceed 180* smoker IT or you could have a fat-out of the meat.
At times i pull the sticks at 149-150 IT and let them at room temp (no cold water) they will IT to 152* by them self.
This is how i do it. Sometimes the times are shorter. Your results may vary.
Yes its a long time but you will like the end results.
That should give you the results you want on your next batch of sticks