Spark disappears from taskbar

I have looked around and have not found the answer so I truly apologize if this has already been asked.

I have one user that is having their Spark icon disappear from the tray a couple times a day and the program will not re-open for a while (though the chat window will still pop up if someone messages them). We have not been able to track it down to a specific action causing it. It just is gone for a while then comes back without intervention sometimes.

I have not found anything that correlates to this happening in any logs. We have uninstalled and reinstalled the program. We are using I have deleted all of her transcripts in case it was a corrupted history and it is still happening. When I uninstalled and reinstalled I made sure to delete the Spark folders from Appdata for that user.

I am at a loss as to what the cause may be and was hoping for any insights folks may be able to offer.