The "# of Accounts" column for under the customer list does not match the number of AWS accounts assigned to the channel customer's billing block/s.
The reason they don't may be due to any of the following:
AWS accounts configured directly at customer level.
AWS Accounts that have been unassigned from channel customer's billing block, but the Accounts will still show at customer level because they have incurred costs in the last 13 months.
The "# of Accounts" column is a reflection of the number of AWS accounts listed in the channel customer's AWS Accounts page here https://apps.cloudhealthtech.com/aws_accounts