Is there any reason these remain separate logins?
If I am accessing Communities from the waffle icon once I have signed on with a federated sign in ,I would expect my log in to pervade other Bentley web services
This was done by design since Communities allows for Guest Access. This is why you need to click on 'Sign in". This holds true for us as Bentley Colleagues as well.
Thanks for your answer that helps me a lot!