Hello @Oetze van den Broek,
Thanks for waiting on this issue!
Please send an email to azcommunity@microsoft.com with the below details, so that we can work offline on this issue to collect more detailed information and unblock your issue.
Thread URL: Link to this thread.
Your Azure Subscription ID:
Email Subject : Attn Satish Boddu
Please let me know once you have done the same
Additional information which might be useful for other community members!
Make sure that the device has a stable network connectivity and is properly reporting its update status to the IoT hub by checking the device's twin properties in the IoT hub. If possible please verify the IoTHub and Device logs for any reported issues! Device update needs stable connection during update process, please make sure there are no disconnections during update process.
Also please refer to : Device Update for IoT Hub Troubleshooting Guide
Similar questions: How does the Azure IoT ADU service determine when an update succeeded?