The DC Circuit just issued an order for the counsel in Flynn to be prepared to answer questions about mandatory recusal or removal conditions for judges... https://jonathanturley.org/2020/06/28/making-trouble-how-the-flynn-case-became-a-dangerous-game-of-legal-improvisation/

...The only potentially applicable part of 28 U.S.C. 455 includes mandatory recusal "where he has a personal bias or prejudice concerning a party, or personal knowledge of disputed evidentiary facts concerning the proceeding."
https://www.law.cornell.edu/uscode/text/28/455

The order is interesting because the briefing already raises bias, but the order is preparing for argument on whether this was not just a case of judicial error but a matter for mandatory disqualification. It is the difference between judging wrong and the wrong judge in a case.