The ‘Activity type’ / ‘donation problem’ summary in the Dashboard, only shows one time donations. As an alternative, you could filter for donors who have an active recurring donation, but haven’t had a donation processed in the last month —you can do this by using filtering criteria such as: ‘Recurring donation status’ is ‘active’ and ‘Date of most recent donation’ ‘is before or on’ (today’s date). That would filter for people who have an active recurring donation that hasn’t gone through for a set period of time.