Hello Prashan,
That's a funny coincidence, I noticed the exact same issue earlier today.
I spent a few hours scratching my head and switching between the Meraki dashboard and our Cisco ISE (which handles the RADIUS requests) and I finally figured out what was the issue.
In our case: all our ISE policies start with a "if Wireless_802.1X". This checks two things from the RADIUS request fields:
- NAS-Port-Type = Wireless-802.11
- Service-Type = Framed
Interestingly enough, it turns out that if you use the "Test" button the Meraki AP will not include the "Service-Type" information in its RADIUS request. Because of that the request does not pass the "if Wireless_802.1X" condition and is rejected.
You can see this behavior with a packet capture of the AP uplink port. As you can see below only the NAS-Port-Type is sent:
However during a real user authentication, the AP correctly sends both information to the RADIUS server so the authentication is working fine.
So I would check whether you are also using the "Wireless_802.1X" condition on your RADIUS server or not.