Wrong path to files in subsites

In media library paths to files are incorrect - this is only happening on subsites, the main site has the correct paths: https://site.com/wp-content/uploads/2017/09/file.png
Subsites have: https://site.com/subsite/files/2017/09/file.png
We run plugin conflict test also checked if in wp-config.php there is no

define( 'UPLOADS', 'files' );

(there isn't).