I would say running conventional or not enough smoke fluid is the issue.
I have the 10 wheeler from the year before and it smokes great in command. The recommended 15 to 20 drops of smoke fluid is not enough.
I did around 30 drops or so and it smokes great along with the whistle steam. 15 to 20 drops of fluid is not enough in a new fan driven smoke unit.
Just my opinion and experience.
Brad