is working but MacOs recently has autoplay policy for user: https://webkit.org/blog/7734/auto-play-policy-changes-for-macos/, I resolved the same issue using a button to enable sound:
ejm:
<video autoplay loop muted id="myVideo">_x000D_
<source src="amazon.mp4" type="video/mp4">_x000D_
Sorry, your browser doesn't support embedded videos..._x000D_
</video>_x000D_
_x000D_
<button class="pausee" onclick="disableMute()" type="button">Enable sound</button>_x000D_
_x000D_
<script>_x000D_
var vid = document.getElementById("myVideo");_x000D_
function disableMute() { _x000D_
vid.muted = false;_x000D_
}_x000D_
</script>
_x000D_