Hello @Caroline375,
When I looked at your listing it seems that the base price is set to €89 and the calendar price for each day is set to €57.
There is no monthly discount set. If a monthly discount is set it will show in the "Prices section" seen in the screenshot below.
It also shows the price for the 20th of August as €57.
The usual way to set a monthly rate is to specify a monthly discount. Go to "pricing settings" on the calendar and click on "Edit" in the "Length-of-stay prices" section to set a monthly discount.
I may be wrong but it looks llike the base price is set to €89. This is the price set when you go to your calendar and select "pricing settings" and then click on the "Edit" button in the "Nightly price" section. That's the price that shows when guests search but before they enter any dates.
It looks like €57 is set as the calendar price. If you click on a date on the calendar does the price show as €57?
If so then that's why guests booking short term stays like one night get that rate.
If the above explains what's wrong then you should:
1) change the price for all calendar dates to be €87. You can click on the first date and then enter start and end dates and the new price.
2) set a monthly discount percentage in the "Lenght-of-stay prices" section of "pricing settings" on your calendar.
Hope that helps.
Steve.