hi,
The answer is in the user guide:
chapter 10.16.2, last paragraph:
"When a single player wins your tournament, they will not have a bust out time. Because of this, if there is a single tournament winner, you may not be able to move this player within the rankings. If it was your intention to have a different winner, you should correct this by undoing the bust out of the true winner and then busting out the previously incorrect winner. "