I agree that when a stove or oven is first used you can get some burn off of oils used in making the thing.. but only the 1st time
One thing many forget,,, the range hood is vented to the outside but there is a "Door" often outside (BUT NOT ALWAYS) that needs to be "unlocked"
On the outside door or flapper if you like there are two cam locks one on either sidek they have to be rotated out so as to let the flapper flap
On mine the flapper is INSIDE and there is a spring up under the hood you have to PULL OUT to unlock it
If it's locked closed it wont' exhaust.