Mikrotik RB951ui RADIUS accounting request not sent: no response

Hi, anyone knows how to fix this issue when using hotspot authentication + Radius server ?
I turned accounting on but mikrotik doesn’t even send the request (nothing arrives at the radius server)

15:11:18 hotspot,info,debug AA:BB:CC:DD:EE:FF (10.5.50.254): trying to log in by mac 
15:11:18 hotspot,account,info,debug AA:BB:CC:DD:EE:FF (10.5.50.254): logged in 
15:11:48 hotspot,warning,debug AA:BB:CC:DD:EE:FF (10.5.50.254): RADIUS accounting request not sent: no response 
15:12:44 hotspot,info,debug AA:BB:CC:DD:EE:FF (10.5.50.254): logged out: idle timeout 
15:12:48 hotspot,error,info,debug AA:BB:CC:DD:EE:FF (10.5.50.254): RADIUS accounting stop request not sent: no response 
15:13:14 hotspot,error,info,debug AA:BB:CC:DD:EE:FF (10.5.50.254): RADIUS accounting stop request not sent: no response