I don't know if you ever figured this out, but I just troubleshot a similar issue myself with remember-me not working and it came down to the User Entity getUserIdentifier function not returning exactly what the remember-me system was expecting. In my case I had imported most of the user auth system from a previous project, and that one wasn't case sensitive, so all usernames were returned as lowercase, while the current project was case sensitive meaning it expected getUserIdentifier to, in my case, exactly match getUsername.