@Lisa6418 Airbnb does not set your prices, you do. I have read a couple other posts saying this happened to other hosts, too, though. There was a comment that Airbnb is doing this hoping hosts won't notice.
Contact customer service to try to find out what's going on. No way are they allowed to override host's pricing and if you get bookings at the wrong price, make Airbnb cancel them with no penalties to you.