Is Keycloak auth fully working?

Description:

I set up Keycloak authentication and noticed that not all functions work
Keycloak is a SSO provider, which means not only a user provider, but also provides additional features such as Singel Sign In and Single Sign Out between all applications connected to Keycloak.

Steps to reproduce:

1. I have my custom app which connected to Keycloak
2. I have my Rocket chat which connected to Keycloak by this guide
3. I did login in my custom app
4. I go to Rocket chat and see login page which requires login or Keycloak login button
5. I go to Keycloak login button and anyway should login
6. After login to Rocket chat I tested logout (it should logout ALL Keycloak apps)
7. I did Rocket Chat logout
8. I tried login again I rocket chat and right after clicking Keycloak login button its login without asking me a username and password

Expected behavior:

I expected that Rocket Chat can be working with Keycloak Single Sign On and Single Sign Out

1. I expected that after login with Keycloak in my custom app on step 1 it's will NOT require me to login again in my Rocket Chat
2. I expected that after logout in Rocket Chat it will also logout in my custom app (both connected to one Keycloak Realm)
3. Is it possible to have only one login method? I mean step 4, can it be only Keycloak login form(not require click Keycloak login button)

Actual behavior:

Actual behavior is Keycloak work with Rocket Chat Only like users provider and not like full SSO
Is it any way how to do Single Sign On and Single Sign Out too?

Server Setup Information:

• Version of Rocket.Chat Server: 4.5.0
• Operating System: ubuntu 20.04
• Deployment Method: docker-compose
• Number of Running Instances: 1
• DB Replicaset Oplog:
• NodeJS Version: 14.18.3 - x64
• MongoDB Version: 4.0.28

Client Setup Information

• Desktop App or Browser Version: Google Chrome
• Operating System: Windows 10

Additional context

Relevant logs:

The issue names no repository files or tests. Start by reviewing the linked Keycloak OpenID Connect setup guide and reproducing the numbered login and logout steps; done means determining whether Rocket.Chat supports the requested single sign-on, single sign-out, and login-method behavior.