Hello @Catherine-and-Simon0,
There ia a specific place where you can add your cleaning fee.
Go to your calendar and click on "Pricing settings".
Then click on "Extra charges and currency".
A little box will then appear.
Enter your cleaning fee amount there.
I found that the little up and down arrows, to increase or decrease the amount, work only in the Google Chrome browser.
For other browsers like Firefox and Microsoft's one you have to manually type in the amount and then click somewhere on that grey window. The word "saved!" should then briefly appear in green at the top beside the "Pricing settings" heading.
After doing this check that your listing preview shows the cleaning fee charge.
Steve.