nginx with reverse-proxy and wildcard-subdomains - nginx

Question

I become desparate... I want to write a configuration for nginx where shell.foo.org use a reverse proxy and *.shell.foo.org use a wildcard subdomain, so e.g. name1.shell.foo.org read /var/www/name1.shell.foo.org and name2.shell.foo.org read /var/www/name2.shell.foo.org. I tried a lot of versions but either the reverse proxy work or the wildcard subdomains.
My nginx-configuration is:
server {
listen 80;
listen [::]:80;
server_name ~^(www\.)(?<subdomain>.+).shell.foo.org$
~^(?<subdomain>.+).shell.foo.org$ ;
return 301 https://$host$request_uri;
}
server {
# SSL configuration
#
listen [::]:443 ssl ipv6only=on;
listen 443 ssl;
server_name ~^(www\.)(?<subdomain>.+).shell.foo.org$
~^(?<subdomain>.+).shell.foo.org$ ;
ssl_certificate /etc/letsencrypt/live/shell.foo.org/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/shell.foo.org/privkey.pem;
include /etc/letsencrypt/options-ssl-nginx.conf;
ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
if ($scheme != "https") {
return 301 https://$host$request_uri;
}
root /var/www/$subdomain;
index index.html index.htm;
location / {
# if I comment this out the wildcard subdomains work;
# in this version, the reverse proxy work
proxy_pass http://127.0.0.1:8080;
proxy_http_version 1.1;
proxy_read_timeout 300;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
proxy_set_header Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Real-PORT $remote_port;
}
root /var/www/$subdomain;
index index.html index.htm;
}
Anyone an idea where my mistake is?
Thanks,
bengoshi