This may only be when loading games from the last patch, but I noticed that on my current game, every time I load, the amount of cash in my treasury radically changes. As I was mostly loading my old games to export ships to the new version, I noticed that sometimes the treasury from the previous map would carry over onto the new one. At one point, I had suddenly gained 2000bc out of nowhere.
I'm going to try starting a new map and then loading a previous game to see if my theory is correct, but something's definitely not right. Heads up.