API Rest Put to assign ticket fails with error 4000
{"response_status":{"status_code":4000,"status":"failed","messages":[{"status_code":4000,"message":"Input Json Data not found for entity.","type":"failed"}]}}
When doing this from the API documentation page on our actual server, it works fine.
When running it from a PowerShell script, where I have others API requests that work just fine, it fails with error 4000.
This code for other API requests, such as viewing tickets, works just fine. Even Deletes work. For some reason, assigning does not work. Yes, my account has the permission to do this.