Asterisk 1.6 - Agent locked in the queue

I am experiencing a problem with a somewhat old asterisk kkkk Asterisk 1.6 happens that the user can not log in the queue, and when I access console, I identify that the agent is already logged in. But I have to remove the agent (queue remove member SIP / queue extension) then back to normal the agent enters and leaves the queue quietly, I noticed that every week has been occurring this.

Any idea what that might be?