CDC is not capturing data

I had enabled CDC but nothing is captured in the CDC table, any idea what is the cause?

below is the script that I ran....

EXECUTE SYS.SP_CDC_ENABLE_DB;
GO

EXECUTE SYS.SP_CDC_ENABLE_TABLE @source_schema = 'Metal', @source_name = 'PropertyInstanceValues', @role_name = N'NULL', @supports_net_changes = 1;
GO

EXECUTE SYS.SP_CDC_ENABLE_TABLE @source_schema = 'Metal', @source_name = 'TypeInstances', @role_name = N'NULL', @supports_net_changes = 1;
GO