When I test it, I can see the preview animation on the main page (https://developer.mozilla.org/fr/docs/Web/API/Canvas_API/Tutorial/Basic_animations), but I can reproduce the issue on the page that is launched when clicking < / Play (https://developer.mozilla.org/fr/play). For me, the issue seen on the “Play” page is resolved if I disable “Ask to save and use passkeys” under Settings > Notifications in the Bitwarden browser extension.