Do you have the new IQ5 controller or the IQ4?
Have you cooked anything yet?
If you are just running a brand new pit for the first time, in general, for some reason, temp regulation improves as the unit gets seasoned. Also throw a couple pork butts or a pan of water in there and I think you'll see temps improve with something to act as a heat sink.
Most of the time the IQ4 controller will overshoot if starting at 180 degrees, it will come down over time but takes a while. You can open the door to let heat out and sometimes that will get it there faster. To help reduce overshoot on my IQ4 unit I put a small handful of pellets in the pot and manually light them with a torch, then hit start and let the unit do it's thing. Seems to help reduce overshoot. On my IQ5 unit, I haven't had as big of a problem with overshoot at startup and honestly haven't had much issue running it at any temp. But once the big hunk of metal which is the FEC heats up.. it takes some time to drop back down to 180 degrees...
Nordy