Creditors can report that they have taken a charge-off, and can also report the monthly delinquency status as either the actual level of monthly delinquency, such as 150-late, or as CO.
It is thus entirely proper for a creditor to report the current delinquency status each month as CO if they have previously taken a charge-off, and if the current status remains delinquent. The CRAs provide specific current status code of CO as an alternate to the level of monthly delinquency.
It is not reporting of multiple charge-offs, it is the reporting of continued delinquency status on an account that was previously charged to profit and loss.
If the CO is paid off reporting of it monthly once its updated to 0 balance should stop per CRA rules.