This is my problem also. It started this morning after the update. As long as I am 'in' the game everything runs as normal and the food leaves at a normal pace. I can leave the game and go right back in and ALL the food is gone. I do get the coins for it however. But ... the game isn't fun anymore when you have to keep your door blocked to keep your customer happiness meter at 100% simply because ALL the food vanishes. One of the things I enjoyed about the game was getting to see the customers coming in and eating. I do wish they would fix this.