Temp control in a stick or charcoal burner is all about air control.
One thing to remember with any stick or charcoal burner is adjusting the airflow is sort of like trying to turn a cruise ship. Any adjustment you make takes a few minutes to show up. So make an adjustment and wait several minutes and re-evaluate if further adjustments in the air flow are needed (and which way). Waiting at least 5 minutes would be my recommendation
If you don't wait long enough for the prior adjustment to impact the fire and either choke it back or stoke it up, and then fiddle with the vents again either adding more air or choking it off even more, before you know it you are chasing it all over the place and temps either spike or crash.
Fiddle & wait..... then re-evaluate. This is the key.
On the other hand if you are wanting to target a 225* temp and it's spiked to 350*, it's time to shut the vents down all the way and once the fire is choked way back to around 190-195* then slowly introduce more air to slowly bring it back up. It may continue to fall after you crack the vents a little, but don't panic and give it time. Once you get it stable, it should run pretty solid until the fuel starts to be all used up.