Hi @david wrafter Thanks for posting in our Q&A.
This looks like a conditional access related issue, I find a similar case that others have experienced. Please refer to:
https://learn.microsoft.com/en-us/answers/questions/712177/looking-for-information-on-sign-in-error-code-5300.html
For better troubleshooting, it is recommend to escalate and open a support case. Here is the online support link and hope our issue will be resolved as soon as possible.
https://learn.microsoft.com/en-us/mem/intune/fundamentals/get-support
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