A network engineer configures policy-based routing on R1 to send traffic from the 10.1.1.0/24 subnet through a backup ISP link (next hop 203.0.113.2). The route map uses 'set ip next-hop 203.0.113.2'. During a WAN failure, the primary next hop for the default route goes down, but users on 10.1.1.0/24 report they can still reach the internet through the backup link — however, when the backup ISP link itself fails, those users lose all connectivity even though a valid route exists in the routing table via the primary path. Which change should the engineer make so PBR gracefully falls back to the normal routing table when the backup next hop is unreachable?