It's possible that you were chasing the temperature by changing the vents too often, too. Make small changes and give them time to take effect before making another change.
"Ron Rico, Boss. You can call me Captain Ron..."
Save The Fatty!
FEC-100/BWS Party/Memphis Pro SS/PBC/LBGE X 2/SBGE/Mini BGE/Nomad Pellet-matic/Good-One Model 42/WSM X 2/Cookshack Smokette 008/Weber Performer/Saber Cast 500/Weber Gasser (RIP)/Weber Kettle X 2/Weber Smokey Joe/WGA/UDS/Coffee Roasting Gasser and a pickle
Remembering a friend