XMPP problem after migration

I have migrated my server to a new hardware. I created the users as before (same name, same email addresses, same passwords).
For XMPP, I made a copy of my rosters: /var/lib/metronome/domaine.org. I do have all my contacts and my chats rooms. The only problem is the connection between me and other users on my server. We cannot connect anymore.

Thanks for the help.

Are you sure you were able to connect between your old server’s users before ? (I never tried actually ^^)

Yep, we were able to connect between my old server’s users.

I’ve created two new users and try to make connection between them without success. We can’t see the status of users but we can talk between the two users.