@francis-ducharme-0 You may have to parse the json returned from the get and modify a few things. Does the application get created but not work or does the application not get created? I would think you would need to take the relevant parts from the returned application then create the application under a new tenant? Remember you will have to use the new TenantId in the Request Header. If you are not supplying the TenantId, it will use the default.
On a side note: If you are still interested in a duplicate application across tenant feature in the API, you might want to put a request in.