You noticed that the ID Mapping of "ERP Accounts" in C4C is not being updated after replicating Business Partners from CRM to C4C.
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SAP Cloud for Customer
You have to fill the R/3 Customer number (ID Type CRM002) in the CRM BP under Identification tab as shown below:
ID Mapping CRM ERP CRM002 , KBA , LOD-CRM-INT-CRM , Integration of C4C with CRM , How To