Single Signon Not Working

I tried configuring 2 different applications using keycloak. Both applications are configured under the same realm. Logged into one application in one browser window and opened the other application in another tab. For the second application also, we are getting the login screen. In the log it is showing as:
[org.keycloak.adapters.elytron.ElytronSessionTokenStore] (default task-1) Account was not in session, returning
What does this mean?