Safari iOS 15 video issue

Since I downloaded iOS 15, the video on my page no longer works (in Safari). I used the following code to embed the video.

<video id="video" autoplay="true" loop="true" muted="true" playsinline="true">
    <source src="media/video.mp4" type="video/mp4">
</video>

If I deactivate "GPU Process: Media" in the Safari settings, everything works again as before.

Do I have to embed the video differently?