Lot's of problems?

[KyNola]

David, are you using the thermometer in the door of the OBS to measure the temp?  If so, you are probably getting false readings.  It is notoriously wrong due to the location of it.  Get yourself a digital thermometer where you place a probe with a cable attached inside the tower and read it from outside.  You may find your temps are higher than you may think.  The temp swings can be erratic, especially when the meat is first put in the tower.  As the load comes up to temp you will find the temp swings level out more.