Hi ,
The following article is talking about how to troubleshoot 802.1X authentication, you could have a look:
Advanced troubleshooting 802.1X authentication
For 802.1 X authentication issue, we always need to analyze network traffic to find any clues. However, analysis of network traffic is beyond our forum support level and due to forum security policy, we have no such channel to collect user log information. So we recommend you open a case with MS Professional tech support service, they will help you open a phone or email case to Microsoft, so that you would get a technical support on a one-to-one basis while ensuring private information.
Here is the link:
https://support.microsoft.com/en-us/gp/customer-service-phone-numbers
Best Regards,
Candy
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