HTML5 video not working in Safari 14.0.1 Big Sur?

Question

safari

Greetings.

HTML5 video not working in Safari 14.0.1 Big Sur
In previous versions everything works fine. I must say right away that the problem is not in autoplay, I checked it.

<video poster="assets/756011753.jpg" muted preload="auto" autoplay controls="true" playsinline>
   <source src="assets/999222999.mp4" type="video/mp4" />
   <track src="assets/6121739.vtt" kind="subtitles" srclang="nl" label="Nederlands" default>
</video>