I think once the persistence is configured for a wide IP, the same pool member IP will always be given back to the query for the same LDNS during the persistence period. That is true even when the pool member is down. Could you confirm? I have tried to disable the member as well as the pool. The "tmsh show /gtm persist" still shows the entry for the LDNS for the wide IP. Therefore, I am still getting the same IP as before, even if the member is down... Does it sound about right?