Below is what I found in log not sure why this is happening
2018.06.08 06:14:46 WARN [socket_c2s-thread-3]: org.jivesoftware.openfire.nio.ConnectionHandler - Closing connection due to exception in session: (0x0000008C: nio socket, server, null => 0.0.0.0/0.0.0.0:5222)
org.apache.mina.core.write.WriteToClosedSessionException
at org.apache.mina.core.polling.AbstractPollingIoProcessor.clearWriteRequestQueue(AbstractPollingIoProcessor.java:638)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.removeNow(AbstractPollingIoProcessor.java:590)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.removeSessions(AbstractPollingIoProcessor.java:560)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.access$800(AbstractPollingIoProcessor.java:67)
at org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.run(AbstractPollingIoProcessor.java:1132)
at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:64)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
2018.06.08 06:15:34 WARN [socket_c2s-thread-9]: org.jivesoftware.openfire.nio.OfflinePacketDeliverer - Could not route packet
Can you share client side log as well to suggest some improvement?