After upgrading our environment, we noticed that for some reason many of the cs_id's had changed due to discovery recorrelation.
As a result of the changed cs_id, each system appears twice in Billing/Usage Metering reports - one with the old cs_id and one with the new cs_id.
Release : 20.3
Component : UIM - USAGE_METERING/BILLING
This is expected behavior when the cs_id's change in the middle of a billing period, you will see duplication as both cs_id's are represented.
The following month's report will be back to normal and should only show a single cs_id for each entry.