@Abdulbasıt Gülşen Apologies for the delayed response, was able to setup the dev instance of SAP Cloud Identity Systems at my end and tested the above scenario by creating this mapping urn:ietf:params:scim:schemas:extension:sap:2.0:User:userUuid ---> objectGuid
Though the provisioning on demand picks the attribute and shows as updated in the provisioning logs however Global User ID (which is UserUUID) in SAP is not getting updated.
Have you engaged SAP support team to review/debug this issue from their end?
Also, send me an email to 'AzCommunity@microsoft.com' with Sub - Attn: Givary and following details in the email body: Link to this thread/post We can connect offline and discuss further on this.