In the mean time, it may work if you clear all of month 7 and have the game over screen send you to the main menu. After that it should let you choose month 7 from the scene select.
I just tried that and it didn't work. I played all the way through month 7 and let it take me back to the main menu. From there I went back to scene select, and month 5 was still the last option available.
