NGINX reverse proxy to ASP.NET Core web app 404 static files

Have a basic hello world ASP.NET Core web app with the only modifications being to program.cs -> removed httpsredirect and hsts so it's set up for http.

Published to an Ubuntu server under /var/www/hello_world with static files under /var/www/hello_world/wwwroot. The app sits behind a NGINX reverse proxy to the kestrel server listening on http://127.0.0.1:5000. Everything works fine for the main endpoint, but everything else (css|js|lib|.ico) returns a 404 unless I specify the static files directory in a separate location directive:

location ~* /(css|js|lib) { root /var/www/hello_world/wwwroot; }

I've tried setting up my nginx.conf in both an upstream configuration:

    server  {
    listen 443 ssl http2 default_server;
    listen [::]:443 ssl http2 default_server;

    ssl_certificate /etc/ssl/certs/hello_world.pem;
    ssl_certificate_key /etc/ssl/private/hello_world.key;

    location / {
        proxy_pass http://dotnet;
        proxy_set_header Host $host;
    }
}
    upstream dotnet {
    zone dotnet 64k;
    server 127.0.0.1:5000;
}

and a straight-forward proxy_pass:

server  {
    listen 443 ssl;
    server_name helloworld.com;
    ssl_certificate /etc/ssl/certs/hello_world.pem;
    ssl_certificate_key /etc/ssl/private/hello_world.key;
    ssl_dhparam /etc/nginx/dhparam.pem;
    location / {
        proxy_pass  http://127.0.0.1:5000/;
        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;
    }

    # returns 404 for static files unless I have this
    location ~* /(css|js|lib|ico) {
        root /var/www/hello_world/wwwroot;
    }
}

I can see the shell info from dotnet that the directory structure is correct in the request that is getting passed to kestrel, but kestrel returns a 404 unless I add the location in the nginx.conf. Since none of the guides either from NGINX or Microsoft have this location block I'm assuming I configured something incorrectly. The way I assumed it would work is everything going to that server block with the location / would get passed to kestrel which the ASP.NET Core app would have the directory structure mapped and return the static files.

Any ideas?