Thank you for posting in Microsoft Q&A forum.
Firstly, we may try to clear browser's cache and cookies and then attempt to renew the key again. If that doesn't work, try using a different browser such as Internet Explorer or Firefox to complete the renew process. Alternatively, try using the Azure portal's "New client secret" option to renew the secret key as explained here:
https://video2.skills-academy.com/en-us/troubleshoot/azure/general/invalid-client-secret#resolution
If none of those steps work, it's possible that there could be an issue with SCCM or Azure and you may need to contact Microsoft support for further assistance.
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