When set to Disabled, a node or pool member continues to process persistent and active connections. It can accept new connections only if the connections belong to an existing persistence session.
When set to Forced Offline, a node or pool member allows existing connections to time out, but no new connections are allowed.
Command based on maybe client ip address, verify if client still remains in persist-table
tmsh show /ltm persistence persist-records client-addr %client_IP%