Hi Simmerman, Chip,
Could you please check the knowledge check and confirm that it is working fine without any 400 errors. As it is working fine from our end.
If you have further and issue, please don't hesitate to reach out to us if you have any further queries. I hope the information provided has been helpful to you! If so, please accept the answer by clicking the Accept Answer / Upvote on the post. We value your feedback, and it will help to assist others who might have a similar query. Thank you for your contribution in enhancing Microsoft Q&A!