After installing in a subfolder, the dashboard report cannot be viewed

[Swilder]

After I configure the installation as a subfolder, the admin dashboard cannot view the charts

My app.yml file:

templates:
  - "templates/redis.template.yml"
  - "templates/web.template.yml"
  - "templates/web.socketed.template.yml"
expose:
  # - "80:80"   # http
  # - "443:443" # https

params:
  db_default_text_search_config: "pg_catalog.english"

env:
  LC_ALL: en_US.UTF-8
  LANG: en_US.UTF-8
  LANGUAGE: en_US.UTF-8
  DISCOURSE_DEFAULT_LOCALE: en
  DISCOURSE_DB_USERNAME: username
  DISCOURSE_DB_PASSWORD: password
  DISCOURSE_DB_HOST: db.example.com
  DISCOURSE_DB_NAME: discourse

  DISCOURSE_HOSTNAME: 'www.example.com'
  DISCOURSE_RELATIVE_URL_ROOT: /forum
  DISCOURSE_FORCE_HTTPS: true

  DISCOURSE_DEVELOPER_EMAILS: 'dev@example.com'

  DISCOURSE_SMTP_ADDRESS: email.example.com
  DISCOURSE_SMTP_PORT: 587
  DISCOURSE_SMTP_USER_NAME: username
  DISCOURSE_SMTP_PASSWORD: password
  DISCOURSE_NOTIFICATION_EMAIL: noreply@example.com

volumes:
  - volume:
      host: /opt/discourse/shared/standalone
      guest: /shared
  - volume:
      host: /opt/discourse/shared/standalone/log/var-log
      guest: /var/log

hooks:
  after_code:
    - exec:
        cd: $home/plugins
        cmd:
          - git clone https://github.com/discourse/docker_manager.git
          - git clone https://github.com/discourse/discourse-adplugin.git
          - git clone https://github.com/discourse/discourse-solved.git
          - git clone https://github.com/discourse/discourse-reactions.git

run:
  - exec: echo "Beginning of custom commands"
  - exec:
      cd: $home
      cmd:
        - mkdir -p public/forum
        - cd public/forum && ln -s ../uploads && ln -s ../backups
  - replace:
      global: true
      filename: /etc/nginx/conf.d/discourse.conf
      from: proxy_pass http://discourse;
      to: |
        rewrite ^/(.*)$ /forum/$1 break;
        proxy_pass http://discourse;
  - replace:
      filename: /etc/nginx/conf.d/discourse.conf
      from: etag off;
      to: |
        etag off;
        location /forum {
            rewrite ^/forum/?(.*)$ /$1;
        }
  - replace:
      filename: /etc/nginx/conf.d/discourse.conf
      from: $proxy_add_x_forwarded_for
      to: $http_x_real_ip
      global: true

  - exec: rails r "SiteSetting.notification_email='noreply@example.com'"
  - exec: echo "End of custom commands"

nginx configuration for domain www.example.com:

server
{
    listen 443 ssl http2;
    server_name  www.example.com;

    ssl_certificate_key       /opt/nginx/certs/example.com.key;
    ssl_certificate           /opt/nginx/certs/example.com.crt;

    ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE:ECDH:AES:HIGH:!NULL:!aNULL:!MD5:!ADH:!RC4:!DH:!DHE;
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_prefer_server_ciphers on;

    # ...

    location ~ ^/forum {
        proxy_pass http://unix:/opt/discourse/shared/standalone/nginx.http.sock:;
        proxy_set_header Host $http_host;
        proxy_http_version 1.1;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto https;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header Accept-Encoding $http_accept_encoding;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
    }
}

DevTools shows request failure like:

DevTools failed to load source map: Could not load content for https://www.example.com/forum/assets/start-discourse-ad6df1f90fead75ae210773db99bd88b11531a12b1facaf51e5e1ee650a2cf79.map: Connection error: net::ERR_CONNECTION_CLOSED
...
The FetchEvent for "https://www.example.com/forum/admin/reports/bulk?reports%5Bvisits%5D%5Bfacets%5D%5B%5D=prev_period&reports%5Bvisits%5D%5Bstart_date%5D=2022-06-06&reports%5Bvisits%5D%5Bend_date%5D=2022-07-06&reports%5Btime_to_first_response%5D%5Bfacets%5D%5B%5D=prev_period&reports%5Btime_to_first_response%5D%5Bstart_date%5D=2022-06-06&reports%5Btime_to_first_response%5D%5Bend_date%5D=2022-07-06&reports%5Blikes%5D%5Bfacets%5D%5B%5D=prev_period&reports%5Blikes%5D%5Bstart_date%5D=2022-06-06&reports%5Blikes%5D%5Bend_date%5D=2022-07-06&reports%5Bflags%5D%5Bfacets%5D%5B%5D=prev_period&reports%5Bflags%5D%5Bstart_date%5D=2022-06-06&reports%5Bflags%5D%5Bend_date%5D=2022-07-06" resulted in a network error response: the promise was rejected.

NetworkFirst.mjs:167 Uncaught (in promise) no-response: no-response :: [{"url":"https://www.example.com/forum/admin/reports/bulk?reports%5Bvisits%5D%5Bfacets%5D%5B%5D=prev_period&reports%5Bvisits%5D%5Bstart_date%5D=2022-06-06&reports%5Bvisits%5D%5Bend_date%5D=2022-07-06&reports%5Btime_to_first_response%5D%5Bfacets%5D%5B%5D=prev_period&reports%5Btime_to_first_response%5D%5Bstart_date%5D=2022-06-06&reports%5Btime_to_first_response%5D%5Bend_date%5D=2022-07-06&reports%5Blikes%5D%5Bfacets%5D%5B%5D=prev_period&reports%5Blikes%5D%5Bstart_date%5D=2022-06-06&reports%5Blikes%5D%5Bend_date%5D=2022-07-06&reports%5Bflags%5D%5Bfacets%5D%5B%5D=prev_period&reports%5Bflags%5D%5Bstart_date%5D=2022-06-06&reports%5Bflags%5D%5Bend_date%5D=2022-07-06"}]
    at a.makeRequest (https://www.example.com/forum/javascripts/workbox/workbox-strategies.prod.js:1:2145)

...

[Falco]

What’s the error code for the failed request on the network tab?

Anything related in the /logs page?

[Swilder]

just shows faild.

In the /logs page, only one line:

An attempt was to change notification_email SiteSetting to noreply@example.com however it is shadowed so this will be ignored!

[Falco]

Whats the error code?

[Swilder]

After double-checking the nginx configuration, I found that the request headers were too large, so I changed the server configuration and the problem was solved, thanks!

server {
    ...
    client_header_buffer_size 8k;
    large_client_header_buffers 4 32k;
    ...
}