WOW I hope airbnb is paying attention to this thread. This seems to be a problem all over the world!! So far... my accidental and expreimental actions have, at least temporarily, solved my problem. First of all... I used my lap top not the cell phone app.
This has been my experience for solving the same problem: First I made certain "auto pricing" was turned off. I went to my calendar. At first I had trouble highlighting a block of days so I went day by day. I highlighted that day on the calendar, used the drop down menu in the upper right corner, set my price, scrolled down. The "save" option was mostly covered by an advertising bar across the bottom but I could see the edges of it. I clicked on "save" and it saved my pricing.
I am curious if we all get the same process and airbnb pages even if we are in different countries.
Just an FYI, my daughter was having the same problem. It almost never happens that I would be the one coaching her on a technical issue!! However, she was using her smart phone and I was using my lap top. It was much easier to figure all this out on the lap top. Once she worked on her lap top she had a much easier time.