in-active users needs to be manually kicked out

Greetings,

I am having problems regarding inactive users. I am currently using DALO radius for authentication and it works pretty well so far. But hotspot users sometimes have a problem re-authenticating back to the portal because their mac address is still in the controller, idle session cut off is set on 5 mins. I have to manually kick them out of the controller so they can re-login again. Any advice on what to do? Thanks in advance.