The strength of memory challenge is "if a player has shot the same eye twice -> fail challenge".
To complete this challenge in previous seasons we would have 1 person on each side shoot both eyes on the bottom floors. Then have the remaining guardians who haven't shot any eyes shoot the 6 eyes at the top floor.
When doing this challenge today (18/11/2020) whenever we shot any eyes at the top floor it would fail the challenge.
Legit riven challenge is a well thought out challenge and I hope bungie can fix it so that the very few of us who still do legit riven can complete it as it was intended.