Really sad so many are having this problem!
I think there is a bug in the communication between the listing price on the "pricing, etc." page and the calendar. Since the calendar is constantly trying to get you to go with the random prices it suggests, you are able to change your price there. However, this doesn't change the price of your listing on the other page...
I still can't quite figure out how Airbnb decides to charge folks for monthly stays though. Three out of 4 times, I can't get the same price as them no matter how many combinations of numbers I use. I have contacted CS about this and have not heard back.