Azure's SCIM implementation when creating a user who has a manager follows this approach:
1. Create the new SCIM user (without the manager reference)
2. Make sure the new user has been created
3. Update the new user's manager field
It seems the reason for this approach is because Azure wants to create all the users first, before it tries to add references to them via the manager field (which makes sense from a referential integrity perspective).
However, when using the UNIFYBroker SCIM gateway, step 2 is failing and Azure can't find the newly created user. Azure first tries to get the new user object by ID, and then by username lookup, but neither works. See the attached packet trace "SCIM User with manager creation.pcapng" for details. The connector/adapter entity created has the same entity ID that was returned to Azure (9a9978e0-6179-42b5-8218-2173d7b6c0e5 in the packet trace) and the username field set correctly (firstname.lastname@example.org).
A later attempt by Azure to look up that entity by username (package trace "SCIM User lookup.pcapng") is successful (that lookup was followed by a PATCH which failed, but that is due to a different issue so please ignore that part of the trace).
This github ticket has information about the Azure SCIM pattern for setting manager: https://github.com/MicrosoftDocs/azure-docs/issues/11784 (comment from asmalser-msft)
Customer support service by UserEcho