You probably have a queue member for that extension, fop2 will rename labels based on queue member names if they have any. Run:
asterisk -rx "queue show"
And see the entry for that particular extension, it will probably show Local/7009@from-queue (7009) or similar. In that case, edit the queue, remove the member, apply changes, add the member again and add changes so it gets the new extension name (that's a freepbx feature/bug, where queue member names are not changed if you change the extension name).