One resource disconnecting causes all resources to appear 'Offline', when in fact user is still online via at least one resource

Description:

User A is connected to openfire via two different resources, let’s say a@example\mobile, a@example\work. User A is on User B’s roster, thus when User A logged in originally, User B could see that User A was online. User A then closes the a@example\mobile connection to openfire.

Expected Results:

User A still appears online to User B because User A is still connected to openfire via a@example\work.

Actual results:

User A appears offline to user User B even though openfire knows User A is still connected and online via a@example\work.

Question:

How to configure openfire or alternatively a custom client to enable the expected results.

Any thoughts much appreciated!

Ian Serlin