HTML5 Error ONLY on Home page

I’ve just installed this excellent plugin, configured a new video with an HLS source based on a custom CDN (the m3u8 playlist is hosted on a different server) and embedded the resulting shortcode on a sample post. Everything’s fine except that on the wordpress home page (main loop) the player returns “HTML5 Unsupported Video Format: Try installing Adobe Flash.
Tried on Chrome, Firefox and Safari.

Why does it work only on the single.php template and not on the index.php (homepage) ?

Thank You.