R6900P Circle passcode issue

Netgear has set up a community forum specifically for the Circle product. Most of the people who watch that forum are more likely to have experience with Circle and know how to work it better than those of us who follow this "general Orbi" forum. Might be more likely to find someone who has a solution if the question is posted there:
https://community.netgear.com/t5/Circle-Smart-Parental-Controls/bd-p/en-home-circle

You'll need to contact a forum moderator there. You'll need to send them the routers serial # and email account associated with the Circle app. 

Good Luck.