DigiQ II issues

I have had the DigiQ for about 6 weeks and did a couple long slow / low cooks (pit at 225) and it worked OK.

Yesterday I cooked a 20 lb turkey on a Lg BGE - I set the DigiQ pit to 320 degrees (range 32 - 425 within 2 deg per book).

The 1st thing that happened was the pit got up to 380 and the HI alarm went off, I got the pit to settle down and everything was looking good holding at 320 - the 10 cfm blower would come on every now and then. The food probe was in the beast of the turkey and was reading 160 after a couple of hours, Then after another the food probe was reading 180 - so I checked the meat with a Thermapen and it read 150 - then I read the meat temp with a polder and it said 150. I tried resetting the food probe by unplugging and plugging back in - this did not help. So I hooked a polder to the meat, thinking that the food probe was bad. After a couple of more hours I noticed the meat was now at 174 and the dome temp was 250 - the DigiQ pit said it was 320.
After a little while the BGE dome temp was 225 and the DigiQ said 320 - so I increased the pit to 350 - the blower started and I thought it was OK. So after about a hour the dome temp fell to 200 and the DigiQ said 350 - I opened the lid and the fire was out.

I tested the probes this morning with boiling water and the pit probe got close within 10 degrees and the food probe was the same within 10 degrees.

I am not sure if it is working properly or not. What is going on with the DigiQ?

Sorry for the long post.

Chuck in northern MN