It works fine via PRIME video > P+ subscription. Only way to get 1080p in the U.S., it looks like. Your mileage may vary in other countries, as noted in the posts already describing the issue, including in this thread.
When you post “still no fix,” you might want to include the country you’re from, if using VPN or not, etc. The ability to download HD (1080p) seems to be highly dependent on locale, and not on SF alone.