loading="lazy" attribute bug

[lovor]

Adding of loading="lazy" attribute cannot be prevented; even when placing

add_filter( 'wp_lazy_loading_enabled', '__return_false' );

in functions.php. Further, loading="lazy" is added to all images, event to images in page templates (e.g. header.php), which already have loading="eager" attribute.

[Mista-Flo]

Can't reproduce, I tried to add the filter in a mu-plugin for example, and the lazy load attribute was properly removed.