If you click on the "Export Radius Data" button, you download an excel file, in which you can see which devices are registered in the RADIUS data.
You can test on the RADIUS server, if the device is not only on the list, but also on the server.
Also you can for example look into a list of devices that are on the server:
If you have problems with configuring the switch, you can look for more information here
If the device is stored in the list, but not on the server there is most likely a synchronizing problem.
In this case you can check, if the heartbeat is up-to-date. It should usually only be a few minutes old. If it's older, the server is most certainly not synchronized.