Reseller markup was changed, but not all customer subscription are billed with the updated markup value. The Azure period has already passed for the affected subscriptions, so the new markup should have been applied.
The issue is affected by APSA-19830 (Changed reseller retail rate is not applied to customer) and APSA-20662 (Invalidate tenant data cache after retail rate updated).
The issue is permanently addressed in Azure CSP application version 8.0, consider upgrading the instances.
Contact Odin Support Team to resolve the issue for existing customers.
Contact your TAM or PTA Team (firstname.lastname@example.org) to trace the status of the issue and request a permanent fix.