Hello IBM team!

It appears that the API PATCH contactByLookupField doesn't work like the AddRecipient XML API with SYNC_FIELDS and Update_IF_FOUND parameters but will rather Update the oldest contact matching one of the Look Up fields which makes it impossible to update a specific contact if it shares values in the Look up field with another one if you don't already know its RecipientId / ContactId.

Thank you in advance!