Droping clients from radius (they are connected into radius but they are not connected in their houses)

[K. Hoercher]

There is no such thing as "user remains connected into my radius
server". It's the client's (here PPPoE Server?) responsibility to act
accordingly. In particular it should eventually update the accounting
if a "client"/user is MIA. That might be near to the problem you are
refering to.

Best regards
K .Hoercher