nginx wont proxy_pass to service on 127.0.0.1:8080 with ssl

Question

I am trying to proxy_pass to a local service (fossil scm) on http://127.0.0.1:8080.

• http://scm.domain.de and https://scm.domain.de returns ERR_CONNECTION_REFUSED.

• https://scm.domain.de:8080 returns ERR_SSL_PROTOCOL_ERROR.

• http://scm.domain.de:8080 works fine.

My conf in sites-available looks as follows:

server {
listen 80;
server_name scm.domain.de;
return 301 https://$host$request_uri;
}
server {
    listen 443 ssl;
    server_name scm.domain.de;

    ssl_certificate /etc/letsencrypt/live/scm.domain.de/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/scm.domain.de/privkey.pem;
    include /etc/letsencrypt/options-ssl-nginx.conf;

    location / {
        proxy_pass http://127.0.0.1:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
 }

and my nginx.conf as following:

user www-data;
worker_processes auto;
pid /run/nginx.pid;

events {
    worker_connections 1024;
}

http {
    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    server_names_hash_bucket_size 64;

    server {
    listen 443 ssl default_server;
    server_name _;

    ssl_certificate /etc/letsencrypt/live/scm.domain.de/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/scm.domain.de/privkey.pem;

    return 444;
    }

    server {
        listen 80;
        server_name _;
        return 444;
    }

    include /etc/nginx/sites-enabled/*.conf;
}

Edit: How can I get it to work with https, so I can open the site with https://scm.domain.de ?