Register/ack not sent on failure

So I am trying to actually register my raspberryPI via the open Connector using the AWS MQTT broker. I sent the wrong registration payload, can see the error log in the K8s logs, but the error is not sent over MQTT - however the asyncAPI spec says that it should have been acked with a status "failed".

The error mess:

HTTP response headers: HTTPHeaderDict({'Audit-Id': '40fe1302-de42-40ad-935d-c282caba8eb3', 'Cache-Control': 'no-cache, private', 'Content-Type': 'application/json', 'Warning': '299 - "unknown field \\"spec.name\\"", 299 - "unknown field \\"spec.storage_type\\"", 299 - "unknown field \\"spec.timestamp\\"", 299 - "unknown field \\"status.status\\""', 'X-Kubernetes-Pf-Flowschema-Uid': '0965e350-26b5-4c8b-8400-a4109e30e8df', 'X-Kubernetes-Pf-Prioritylevel-Uid': 'e6c31264-121e-432f-a582-1da5d532c939', 'Date': 'Fri, 22 Aug 2025 09:09:07 GMT', 'Content-Length': '942'})
HTTP response body: {"kind":"Status","apiVersion":"v1","metadata":{},"status":"Failure","message":"DeviceNode.hyper.ai \"ldm-RaspberryPI5\" is invalid: metadata.name: Invalid value: \"ldm-RaspberryPI5\": a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')","reason":"Invalid","details":{"name":"ldm-RaspberryPI5","group":"hyper.ai","kind":"DeviceNode","causes":[{"reason":"FieldValueInvalid","message":"Invalid value: \"ldm-RaspberryPI5\": a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')","field":"metadata.name"}]},"code":422}