I just did the Tinkle Man mission as Franklin. I got the man to the airport on time, then I maxed out all my money on each character on Tinkle stock. Then I saved the game multiple times and went to cash out. I cashed out Trevor and Michael no problem, but then I went to Franklin and discovered that he had purchased NO stock in Tinkle. I thought I must have made a mistake and reloaded my game to before the stock buy. I tried to buy as Franklin, but NO GO. You can try to purchase it, but no money leaves your account. You keep your original money and it is IMPOSSIBLE to invest ANY money in Tinkle at all. This HAS to be a bug, and I NEED it fixed so I can go start buying properties.