Remember that notices can be sent to members at any time according to your delinquency notice configuration. This is independent of the configuration that controls whether a loan is actually considered "delinquent" or not. For example, your credit union might choose to send notices when a loan is 10 days past due, but not truly consider it delinquent for collections purposes until 30 days.
The # of times delinquent counter on the MEMBER5 (for closed-end loans) or MEMBER6 (for open-end loans) file gets updated when the loan goes more than 1 month (30 day) delinquent. So if a loan never goes more than 29 days delinquent, this number would remain at 0. The Member Delinquency Inquiry only shows a loan if the # of times delinquent counter is 1 or more.