Pseudo-online PSI and PSI +

Hello!
I am using openfire server version 4.4.4 and PSI and PSI + 0.7 1.3 1.4 versions clients.
Everything works great, with the exception that some clients appear offline in the roster, they can send messages, but they cannot receive messages until they reconnect. After reconnecting, they begin to receive all missed messages. There is nothing in the server logs that would indicate a problem.
I ask for help where to look for a problem.

That’s a new problem to me. Would it be possible for you to capture the XMPP stanzas (for instance using the XMLDebugger plugin for Openfire) and share that with us?

Thanks for the quick response!
I looked in the debug log and found such lines, but I’m not sure what is connected with them:
DEBUG [socket_c2s_ssl-thread-16]: class org.jivesoftware.openfire.streammanagement.StreamManager[x.x.x.x] - Received acknowledgement from client: h=33897
If there is no choice, I will install the plugin that you specified and share the logs.
Currently, Broadcast and User Import Export plugins are used.
Perhaps I need to provide some other information?
By the way, certificates on the server are valid and non-self-signed.

This line shows that the client is using a feature called “stream management”. It is designed to allow clients to quickly resume a session, when network connectivity drops. It is an optimization that prevents the client from having to re-authenticate, and establish a full new session.

Thanks for the explanation, but this line?
DEBUG [socket_c2s_ssl-thread-14]: class org.jivesoftware.openfire.streammanagement.StreamManager[x.x.x.x] - Requesting acknowledgement from peer, as we have 5 or more unacknowledged stanzas.
In the debug log, I see only those lines and lines that I indicated in the previous message.

That’s logged by the same feature. Nothing to worry about.

I forgot to add, the server and clients are on the local network and do not interact with the Internet.
Ok, thanks for your answers!
I will try to get the logs using the plugin.