Airbnb appear to be a modern well run company but i think using currency shenannigans to fleece customers is incredibly poor and trying to hide sharp commercial practice behind presenting this as an issue of an amatuer or voluntary company is shocking. This is a commercial operation and are required to meet contractual obligations.
It is noteworthy that you can select only one currency at a time. If you select the wrong currency, then you can go back and change it. Once you have selected the proper currency, the airbnb app will automatically take you to the profile screen which you can see your selected currency at the bottom.
My paypal account has default currency of eur and the eur card was linked to it. However, when submitting payment via paypal airbnb kept changing the payment currency back to gbp. Airbnb then charged my credit card several times for this rental despite not finalising payment via paypal, with automated email confirmations they have refunded it.
We booked a house in norfolk, uk for a week, and received confirmation from airbnb.
What i have worked out is that for the past month at least, my airbnb account has been showing everything in usd and not displaying the currency. There was no usd or aud being displayed against the properties i was looking at using the map, no when i save them, nor when i went to pay for them.
It was clearly stated that payment will be processed in usd, however invoice says that youve billed me in gbp instead of usd and 3 conversion fee was included.
After that, select the currency button at the bottom right corner. Now, from the currency selector window select your preferred currency. As you do that, you will see that the prices on your airbnb account will show in the selected currency. So thats how easy it is to change your default currency on airbnb on your desktop.