Openfire Presence Plugin Not Updating a User's Status

We’re running 3.9.3 in prod and have a web app that queries the Presence plugin service to determine a user’s status.

For one user out of 1,000’s (so far) the Presence service perpetually shows green, even if they’re offline or have their status set to Away or DND.

Going directly over XMPP to the server, both our Spark based desktop clients and Converse.js based web clients report the status correctly.

This is a conundrum that I’m hoping someone can give guidance on how to debug.