Can't load static files on Blazor server behind NGINX proxy

Question

I hosted a BlazorServerSide created with .NET5 on Ubuntu 20.04. When I start the app directly with dotnet command, it works fine. However, when it is started by systemd service, the static files are not loaded. The wwwroot directory and its contents do exist. By the way, I have removed the symbolic link to the default file in /etc/nginx/sites-enabled/ . Is this the cause?

nginx config:

server {
        server_name {My_FQDN} www.{My_FQDN};

        location / {
                proxy_pass         http://localhost:5000;
                proxy_http_version 1.1;
                proxy_set_header   Upgrade $http_upgrade;
                proxy_set_header   Connection keep-alive;
                proxy_set_header   Host $host;
                proxy_cache_bypass $http_upgrade;
                proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header   X-Forwarded-Proto $scheme;
        }

    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/www.{My_FQDN}/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/www.{My_FQDN}/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot


}
server {
    if ($host = {My_FQDN}) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


    if ($host = www.{My_FQDN}) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


        server_name {My_FQDN}
        listen 80;
    return 404; # managed by Certbot
}

service file:

[Unit]
Description=MyBlazorApp.
After=local-fs.target

[Service]
Type=simple
ExecStart=/usr/bin/dotnet /home/{username}/{MY_BLAZOR_APP_DIR}/{MY_APP_NAME}.dll
RemainingAfterExit=yes
RestartSec=10
KillSignal=SIGINT
User=www-data
Environment=ASPNETCORE_ENVIRONMENT=Production
Environment=DOTNET_PRINT_TELEMETRY_MESSAGE=false

[Install]
WantedBy=multi-user.target

Answer 1

using Microsoft.AspNetCore.HttpOverrides;

...

app.UseForwardedHeaders(new ForwardedHeadersOptions
{
    ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto
});

app.UseAuthentication();

and Resolved by setting the application directory to /var/www/{AppDir} .