There is a difference in the fogger v4.1 (the old one), v2, v3 (big deck), and v4.4 (the newest which is now called 4.1) Confusing.
The 4.4 (aka 4.1) does have a smaller deck and chimney but allows for more juice. It is a tight spot to work esp with long coils.
Another possibility is you got a...