Issue with X-Robots-Tag and X-Permitted-Cross-Domain-Policies

Hi there. I know there has been a lot of questions about this, but none of them solved my cased. I’m running nextcloud with linuxserver.io image behind the traefik proxy. And I"ve got the dreaded messages of wrong X-Robots-Tag and X-Permitted-Cross-Domain-Policies headers.

But as you can see in the following pictures, if I inspect my network, the headers have the good values :

Any ideas why I still get those warnings?

Thanks in advance for your help

As an additionnal information, if I scan my instance on scan.nextcloud.com, it complains about no header (even though there is no X-Robots-Tag in there, there is at least the X-Permitted-Cross-Domain-Policies)