Null DatasetID when cloning a report through api

When I'm cloning a report on a specific workspace using the api, the datasetID is returning null. Why this is happening? 

VERBOSE: GET https://api.powerbi.com/v1.0/myorg/groups/a008b51a-be32-46ec-a236-d42a05331d8f/reports/dcc398c2-9bdc-4343-bf1c-83a7c80dadec with 0-byte payload

VERBOSE: received -1-byte response of content type application/json; odata.metadata=minimal; odata.streaming=true

VERBOSE: Found!

VERBOSE: @{@odata.context=http://api.powerbi.com/v1.0/myorg/groups/a008b51a-be32-46ec-a236-d42a05331d8f/$metadata#reports/$entity; id=dcc398c2-9bdc-4343-bf1c-83a7c80dadec; reportType=PowerBIReport; name=reportname; webUrl=https://app.powerbi.com/groups/a008b51a-be32-46ec-a236-d42a05331d8f/reports/dcc398c2-9bdc-4343-bf1c-83a7c80dadec; embedUrl=https://app.powerbi.com/reportEmbed?reportId=dcc398c2-9bdc-4343-bf1c-83a7c80dadec&groupId=a008b51a-be32-46ec-a236-d42a05331d8f&w=2&config=ey...; isFromPbix=False; isOwnedByMe=True; datasetId=aa3bf5b8-af51-4c21-9d6d-88242c986098}

VERBOSE: Getting dataset aa3bf5b8-af51-4c21-9d6d-88242c986098...

VERBOSE: GET https://api.powerbi.com/v1.0/myorg/groups/a008b51a-be32-46ec-a236-d42a05331d8f/datasets/aa3bf5b8-af51-4c21-9d6d-88242c986098 with 0-byte payload

VERBOSE: received -1-byte response of content type application/json; odata.metadata=minimal; odata.streaming=true

VERBOSE: Found!

VERBOSE: @{@odata.context=http://api.powerbi.com/v1.0/myorg/groups/a008b51a-be32-46ec-a236-d42a05331d8f/$metadata#datasets/$entity; id=aa3bf5b8-af51-4c21-9d6d-88242c986098; name=reportname; addRowsAPIEnabled=False; configuredBy=user; isRefreshable=False; isEffectiveIdentityRequired=True; isEffectiveIdentityRolesRequired=False; isOnPremGatewayRequired=True; targetStorageMode=Abf}

VERBOSE: Cloning report dcc398c2-9bdc-4343-bf1c-83a7c80dadec...

VERBOSE: System.Collections.Hashtable

VERBOSE: POST https://api.powerbi.com/v1.0/myorg/groups/a008b51a-be32-46ec-a236-d42a05331d8f/reports/dcc398c2-9bdc-4343-bf1c-83a7c80dadec/clone with -1-byte payload

VERBOSE: received -1-byte response of content type application/json; odata.metadata=minimal

VERBOSE: Successful cloned!

VERBOSE: @{@odata.context=http://api.powerbi.com/v1.0/myorg/groups/a008b51a-be32-46ec-a236-d42a05331d8f/$metadata#reports/$entity; id=3ea99a7d-238d-4b95-8f85-cc466b0d4270; reportType=PowerBIReport; name=TempReport_c3b13bc9-3c46-4108-8d6e-6c7730af4d2c; webUrl=https://app.powerbi.com/reports/3ea99a7d-238d-4b95-8f85-cc466b0d4270; embedUrl=https://app.powerbi.com/reportEmbed?reportId=3ea99a7d-238d-4b95-8f85-cc466b0d4270&config=eyJ...; isOwnedByMe=False; datasetId=}