802.1X authentication not working for google Pixel phone and Realme

[SLT-Meraki]

We implemented the Meraki MR36 Wi-Fi solution for one of our campus networks. The Wi-Fi solution is configured with an SSID integrated with Windows Server 2012 NPS. The SSID uses 802.1X authentication.

The problem I encountered is that some mobile devices failed to authenticate, with the error message stating, "RADIUS server rejected the authentication request." This issue was observed with specific phone models, including Google Pixel (Android version 15) and Realme (Android version 15).

I have attempted various troubleshooting steps from the Cisco Meraki side, but their final conclusion was that the RADIUS server rejected the authentication requests. They advised checking the RADIUS server configuration.

Can anyone assist me in resolving this issue, either from the Meraki side or the RADIUS server side? Any suggestions or guidance would be greatly appreciated.

[ww]

First step would be to ask the person who manages the radius server for the logging why it send the reject. 

[SLT-Meraki]

I will check it from the customer and update on this thread.

[BlakeRichardson]

This is off topic slightly but you really should be updating your server from Windows 2012 as it's not longer supported by Microsoft. Given this is providing the authentication  for your network you really want it to be secure.

[PhilipDAth]

On the NPS server, filter the "Security" event log for Event ID 6273.  Read the reason why the RADIUS server said it denied access.