Can't connect with any users


I’ve been looking for a solution for two weeks. But I didn’t find any.
I had set an LDAP (AD) authentification, but for some reasons it stopped working. Users that has been created with AD can’t login, but those who are already logged can still have access to it.
I’ve tired to login as administrator but that doesn’t work neither.
When a user wants to login a message appears : “User not found or incorrect”
So I’ve changed the password of the admin user, restarted all services, and I still cannot access it.
I’ve installed rocketchat on ubuntu as a snap. I’ve tired to run updates and it still not working.

Can anybody help with it ?