Policy Based Routing (PBR) pointing to new interface

Below is the scenario

Firewall has two interfaces connecting F5.

normal path works fine with multiple VIP's configured.

New interface is configured between FW and F5, firewall forwards the request, i could see Syn, Syn, Ack in F5, but Syn, Ack doesnt show up in Firewall.

i suspect if the traffic doesnt take the new interface path.

kindly suggest how can i achieve this.

There is only on route domain as of now.

incoming fw source ip is routed to next hop ip of new interface. (F5 connecting to FW).