I am seeing this on one of my hotspots as well. Hotspot is working, but it is not showing user usage (up and down bandwidth used) . I had to add a firewall filter rule for this setup, as it has more then one network. Before the rule below was added, I was getting a "cannot contact radius server" error.
4 chain=input action=accept protocol=udp src-address=127.0.0.1 dst-address=127.0.0.1 dst-port=1812
Now with that rule, hotspot is working... but no user usage... and I am getting the below error.
15:59:46 hotspot,warning,debug blarkin (192.168.2.203): RADIUS accounting request not sent: no response
15:59:50 hotspot,error,info,debug tabys (192.168.2.126): RADIUS accounting stop request not sent: no response
This is a pretty basic setup.
e2-e4 192.168.3.0/24 (Office Network)
e5 192.168.2.0/24 (HotSpot network) ->radio via ethernet