Apps App update keeps getting rejected for content rating violation?


We are trying to submit an update for our app, but we keep getting this error:

Your app submission has been rejected for a violation of the Google Play Developer Program Policy regarding Content Ratings. If this submission was an update to an existing app, the version published prior to this update is still available in Google Play. Please review the content rating guidelines help article, then retake the content rating questionnaire and resubmit. Additional details have been sent to your account owner's email address.

They emailed us saying our adverts showed gambling. We are using Chartboost ads. We tried redoing the content rating questionnaire, then submitting the update, but it just keeps giving us this error.