Invalid username & password error on admin console despite docker-compose configuration

Configuring the server
1

I have leveraged Keycloak in production mode behind nginx via docker-compose file in my Centos 8 machine. TLS is set in load balancer, not in the machine. But when I try to access admin console in browser with the credentials I provide (KEYCLOAK_ADMIN and KEYCLOAK_ADMIN_PASSWORD) in docker-compose file, it gives “Invalid username or password.” error.

docker-compose.yaml file:

nginx:
    build: ./nginx/.
    container_name: nginx
    ports:
      - "8443:80"
    depends_on:
      - keycloak
    networks:
      - keycloak_nginx_network

keycloak:
image: quay.io/keycloak/keycloak:23.0.4
container_name: keycloak
command: start
restart: always
ports:
  - "8080:8080" 
environment:
  KC_DB: postgres
  KC_DB_URL_HOST: postgres_keycloak
  KC_DB_URL_DATABASE: keycloak
  KC_DB_PASSWORD: postgrespassword
  KC_DB_USERNAME: KeycloakPostgres
  KC_DB_SCHEMA: public
  KC_PROXY: edge
  KEYCLOAK_ADMIN: admin
  KEYCLOAK_ADMIN_PASSWORD: admin
  KC_HOSTNAME_STRICT_HTTPS: "true"
  KC_HOSTNAME_STRICT_BACKCHANNEL: "true"
  KEYCLOAK_FRONTEND_URL: "some-url/auth"
  KC_HOSTNAME_URL: some-url
  KC_HOSTNAME_ADMIN_URL: some-url
depends_on:
  postgres_keycloak:
    condition: service_healthy
networks:
  - keycloak_nginx_network

nginx.conf:

events {}
http {
server {
location / {
 proxy_http_version 1.1;
 proxy_set_header Upgrade $http_upgrade;
 proxy_set_header Connection 'upgrade';
 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;
 proxy_set_header content-type "application/json";

 proxy_buffer_size 128k;
 proxy_buffers 4 256k;
 proxy_busy_buffers_size 256k;
    
 proxy_pass http://keycloak:8080;
 proxy_read_timeout 300s;
 proxy_connect_timeout 300s;
 proxy_send_timeout 300s;   
}
}
}

When I enter username: admin & password: admin in browser, The error definition I get in docker logs:

WARN  [org.keycloak.events] (executor-thread-1) type=LOGIN_ERROR, realmId=some-realm-id, clientId=security-admin-console, userId=null, ipAddress=some-ip, error=user_not_found, auth_method=openid-connect, auth_type=code, redirect_uri=some-uri, code_id=some-code-id

1 row above of this warning it says:

INFO  [org.keycloak.services] (main) KC-SERVICES0009: Added user 'some-user' to realm 'master'

Obviously I have already provided credentials but it keeps giving user_not_found error. I tried some of the suggested solutions like; destroying & recreating docker containers, naming username and password different than “admin” and “password” etc but none of them worked.

But when I run same docker-compose environment variables with start-dev command, somehow it logins.

Anyone who have solution for this?