This is on the Amazon.com website (US)

Okay, I set the flag to Mask as Firefox. I closed and reopened the Opera browser but Amazon samples still do not play. Is there something else I missed or need to do?

Version 12.17. Where do I go to check if opera://flags/#proprietary-media-types-playback is enabled? I don't understand your question about which Amazon. When I go to where you would download or listen to samples of various tracks, that is where I have problems.

This has just occurred in the last couple of months. When I go to sample any mp3 music files, the circle on Amazon just spins but no music plays. Is there a fix for this?