Amigopod servers in a High_Availability cluster are expected to send radius packets over the VIP interface, but instead use the individual server IPs to send packets.
You're seeing RADIUS packets from the Amigopod servers, but never get authentications (accept packet). This is because the NAS device is only configured to handle RADIUS packets from the VIP address. Also, firewall rules might be accepting data only over the VIP address.
This was an issue with the VIP configuration and has been fixed in Amigopod RADIUS plugin 3.3. To update: go to Administrator, Plugin manager, check for updates. If you do not see the update available, please contact support with your Amigopod Subscription IDs.