I just came across an issue with changing quantities of what you're trading with Tobias. For example: 450 bricks for soap. I cannot highlight the bricks and change the quantity up or down at all. This seems to only be affecting the top 4 trade slots. I deleted all of my Export offices and the issue vanished; until Tobias came by and traded. I exited out of my game completely and it allowed me to change quantities; again that was only up till the next time Tobias traded and suddenly the trade quantity was locked. This appears to be an issue on all of the top slots of all my islands currently.