REST API: Error Code 1004 attributing lead to campaign by ID
We're currently receiving error code 1004 while attempting to attribute a lead to a campaign by lead ID. This behavior is unique to a specific client.
We deliver the lead data, the API returns a success response with an ID for that lead, we then use that ID to attribute the lead to a campaign, the API returns a failure: [{"code":"1004","message":"Lead [12345678] not found"}]}
Is there something the client could have done in their campaign setup to have caused this? I've tested on other accounts and campaign delivery is working fine.
Thanks
-Martin