Reassigning a case to another contact_id works when using the API Case update but not on case_create with id
I am trying to re-assign case 123 from contact 456 to contact 789. This works like a charm when I use the Case update API with params case_id 123 and contact_id 789, but if I try to use the Case create with case_id 123 and contact_id 789 I get a DB error "already exists"