Action on service Down : Reselect

You can try to use "Reject" for "Active Service Down".

Reject: Specifies that, if there are no pool members available, the system resets and clears the active connections from the connection table and sends a reset (RST) or Internet Control Message Protocol (ICMP) message. If there are pool members available, the system resets and clears the active connections, but sends newly arriving connections to the available pool member and does not send RST or ICMP messages.

Reselect: Specifies that the system manages established client connections by moving them to an alternative pool member when monitors mark the original pool member down.