With a little help from the community and reading a lot I am moving forward understanding pangolin, traefik and the middleware-manager, thank you all.
I use middleware-manager V2 and attached custom headers to my nextcloud resource, they are shown on the traefik dashboard, example Strict-Transport-Security: max-age=31536000; includeSubDomains
Nextcloud still tells me they are not set, I checked with dnschecker.org, they seem to be set.
Where is my error?
please hare your headers and how you applied it. some config file sharing is needed to help better.
@hhf.technoloy In the middleware dashboard, I created a new middleware,
named it nextcloud security header
Type is HTTP Header with following content
{
"browserXssFilter": true,
"contentTypeNosniff": true,
"customFrameOptionsValue": "SAMEORIGIN",
"customResponseHeaders": {
"Referrer-Policy": "no-referrer",
"Strict-Transport-Security": "max-age=31536000; includeSubDomains",
"X-Content-Type-Options": "nosniff",
"X-Download-Options": "noopen",
"X-Permitted-Cross-Domain-Policies": "none",
"X-Robots-Tag": "none",
"X-XSS-Protection": "1; mode=block"
}
}
I attached this middleware within the mwm dashboard to my existing pangolin resource.
Checked the traefik dashboard under routers
any idea what I am doing wrong
headers are working and the middleware manager is also as you can see them in the traefik dashboard. why nextcloud is not taking 
thank you for your look, so I know this configuration is ok. This is one step in the right direction.
Now I have to figure out what I did wrong on the nextcloud.