Azure cost data is missing under both the Partner and Customer tenants for specific subscriptions starting from a particular date for a specific Azure Partner Customer.
This situation may occur if subscriptions are moved to a different Azure Partner Customer or deleted from the Azure Partner Customer. In this case, the cost for such subscriptions will not be collected/present in the Azure bill, so it will not be shown in CloudHealth.
Subscription status can be reviewed via the following areas
1. Asset report
Or
2. Azure Partner Customer