So I have been working on a Rome campaign and really have been enjoying it. One thing that I have noticed though is that when I have city types like Tribute cities or Proconsul cities, I receive a negative income multiplier. I am sometimes getting anywhere from 25% to 35% negative multipliers. It is somewhat the opposite of what I was expecting.

I thought that with the reduced income lost due to autonomy with tribute and proconsul cities, I would in fact receive more money, not less. My federated cities (Allied Cities) don't have these negative multipliers, and instead have the positive income multipliers.

Is there a mechanic I am not aware of that is resulting in the Tribute and Proconsul cities to have these negative multipliers?