Active Sessions count not coming to zero when the Smack clients disconnect abruptly

I am using Openfire 4.2.3 with Smack 4.2.0.

When Smack clients disconnects abruptly, the users are removed from the “Sessions” page but the “Active Sessions count” remains as is. On the “User” Summary screen, the disconnected users are still showing green.
When the Smack clients reconnect after few seconds, it is saying “conflict-cancel” and not letting to connect. The behaviour is same with both “Do not disconnect idle clients” and “Disconnect idle clients after x seconds”. Also clearing the cache from Cache summary screen does not change anything.

Can anyone tell me how to remove these dead sessions?