Lower temp inside the smoker

[randy chiton]

I have a series 4 vertical smoker circa 2019 has been working great but recently I’ve noticed it’s about 50° cooler inside when I’m smoking so if I set it at 250 my other thermometer says it’s only about 200 inside the smoker ( i have check the other thermometer in my oven and it is correct). Anyone else notice or have any idea how to resolve it?

Thanks,

Randy