How far open do you have the holes of the daisy wheel on the top vent?
I am unable to port forward my heatermeter right now but here is a screenshot of yesterday's brisket cook. It is my first run with the roto-damper so a lot of tweaking was going on. It is looking pretty good right now.
After putting the probes in my electric oven at home and setting the oven to 275, I was seeing temperature oscillations of +/- 40 degrees. Not all PID systems are well tuned and you might just now be seeing how well the pellet grill temp control system is tuned.
You will love the UDS, once you finish it.