A Firefox 149.0 UserAgent or UA on Windows 10 and 11 shows as Mozilla/5.0 (Windows '''NT 10.0'''; Win64; x64; rv:148.0) Gecko/20100101 Firefox/149.0 Windows 11 is basically based on the same NT 10.0 as Windows 10 as to why sites may think you are using Windows 10 and not 11. Perhaps when Microsoft actually makes a new version of Windows it will be based on a new NT to avoid this. https://en.wikipedia.org/wiki/Windows_NT#Releases As for Amazon account issues you need to contact Amazon support ex: https://www.amazon.com/gp/help/customer/display.html