Hi, I'm trying KC 5.0.0 running on Java 1.8.0_191 with a newly created Realm simply set up with a custom User Federation (this was tested running "standalone.sh" against the H2 database). When I login (I'm using the "account" client/application but I think this may be irrelevant for this matter) I get two different results: - on some computers I can login and logout several times using any given account. After doing so if I search the user by email in the Users section of KC's admin console I see a single entry. This is fine! - on some other computers, however, I can login for the first time but if I try to login a second time I get a PersistenceException complaining about Unique index or primary key violation (...) ON PUBLIC.USER_ENTITY(REALM_ID, USERNAME) (....). If I search for this user's email on KC's admin console I now see two entries: the one coming from my external source and an extra create by KC. This was also tested on KC 4.8.2 with the exact same results. Have you seen this before? Any ideas about what the problem may be? Regards, Leandro Nunes