How does Amazon/Audible know my country with VPN and private browsing on? - eviltoast

Title.

Trying to buy an audiobook with my US account from Australia. Am using a VPN and a fresh log in using a private browsing window. Still getting the “not for sale in this country…”

How does Amazon/Audible still know my country?!

EDIT: Thank you everyone for your suggestions, but I feel like we’re no closer to figuring out how Amazon is detecting my physical country. If they have some new “trick” surely this is a privacy issue as well?!

EDIT 2: Important details, this is on my iPhone using both the Amazon and Audible apps, and via the web with Safari (mentioned below). Doesn’t work.

I gave up and went to my desktop and was able to complete the purchase following the same steps without issue. So 🤷‍♂️ ?!

Clearly Amazon is scraping some information from the phone to region lock the purchase. Still would love to know given VPN isn’t masking my location apparently.