This issue occurs if the Exchange Server Open Authentication (OAuth) certificate is expired, not present, or not configured correctly.
According to the screenshot of Get-AuthConfig that you provided, the main cause for this issue is not that the certificate expires, but because the Microsoft Exchange Server Auth Certificate is not present.
When you run the set-authconfig command, please replace <ThumbprintFromStep1> with the newly generated Thumbprint by copy-pasting it directly to avoid typing the wrong characters and manually.
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