Conversation sync on multiple devices

Hi everyone.
I just started using the integrated Ejabberd chat in WebTop. Immediatly noticed that conversation are not synced between different devices. To better explain the issue:

User 1:

  • Chat opened on Device 1 - PC
  • Chat opened on Device 2 - Mobile Phone - Astrachat

User 2 sends a message to User 1

User 1 receives the notification and message only on Device 1 or Device 2 depending on
which one is the last used

Is there a way to sync conversation and usage between devices?

Hoping everything is clear.

Best regards,

IMHO is not part of ejabber protocol.
I used Pidgin (jabber protocol) and Hangouts and everything was written on pidgin was available on Hangout, but not vice-versa because of jabber protocol, who (i think) deliver message, not sync the history.