SAML login failed after second trial

Rocketchat version 3.0.2
I configure SAML on Rocketchat. I’m using SimpleSAMLphp as identity Provider. I have followed SimpleSAML configuration as suggested by Rocketchat documentation. I’m using LDAP to store my users.
When i try to login in with a user for the first time, it worked and all user informations are shown correctly. But when i log out and want to log in with the same user, rocketchat redirect me to it’s login page (the user can’t log in again). That is the behavior with all user i create in ldap, the connexion is allowed only once for each user. When i see in rocketchat log, there is no error and i have user informations in the log file.