Unable to send a direct message to a specific individual?

[dpues]

Recently, I can no longer send direct messages to a specific person. I also no longer see the direct chat space with that person. 

When I call that person via Webex, the room appears again for the duration of the call and I can send messages. After the call, the room disappears again.

I can still that person in group chats.

I only have this issue with one person so far.

Any ideas about what is going on?

Answer: looks like I had accidentally hidden the user...

[nitsinh2 · Accepted solution]

Yes, Right-click on the individual contact should have an attribute to hide the user, you can always filter from the image to search for hidden contacts. If needed to un-hide, browsing to the hidden list and Right-click selecting Unhide should fix the user.