Portuguese user able to connect but not visible to other clients

I have a user who is:

  • Able to log on using Spark 2.5.8
  • Visible in the Openfire 3.7.0 “Client Sessions”
    • Authenticated, Online
  • A member of multiple groups
  • Able to send messages and communicate with other users

But he is NOT visible on anyone else’s client (latest Pidgin or Spark 2.5.8) as being online.

Is there something about the characters in his name causing an issue?

Edited poor spelling.

Non-English characters in the username broke things. The displayed name can have anything, but the username must use the alphanumeric English options only.