Fabien

Yes this site is hosted on Cloudways. Your guess was right, I added the following code to functions.php and now I don’t have the warning messages anymore. Thanks a lot.

add_filter('lyte_match_thumburl','lyte_thumbnail_fixer');
function lyte_thumbnail_fixer( $thumb ) {
    return $thumb . '&fix=it';
}

Now I converted all the jpg thumbnails to webp using Shortpixel. However it seems that webp images are not served for the thumbnails (it works for other images on my site, I only have the “Serve images in next-gen formats” message for thumbnail jpgs). I use WP rocket to serve Webp images. Is it compatible with WP Youtube Lyte thumbnails? Or maybe you know another plugin that manages to serve webp for the thumbnails?

Thanks again for your help,
Fabien