Sorry if this relates to the other marketing issues I've already brought up, but this problem is different to what I've experienced so far...
I've noticed that from time to time, some of my marketing budget in random cities disappears. For example: I may be marketing across a wide set of channels in Rome, but then I return a few turns later to find that my newspaper budget has been set to zero. I'm sure of this because whenever I set up a marketing budget in a city, I invest in every available channel and so it's noticeable when suddenly one of them drops to zero. Unfortunately I can't find a pattern in when this occurs.
I've noticed that from time to time, some of my marketing budget in random cities disappears. For example: I may be marketing across a wide set of channels in Rome, but then I return a few turns later to find that my newspaper budget has been set to zero. I'm sure of this because whenever I set up a marketing budget in a city, I invest in every available channel and so it's noticeable when suddenly one of them drops to zero. Unfortunately I can't find a pattern in when this occurs.