The schema check[1] in the LB reconciliation is hardcoded to check the primary Load Balancer only, it will result to always filter the subnets from the schema for the primary, ignoring additional Load Balancers ("SecondaryControlPlaneLoadBalancer")

How to reproduce:

• Create a cluster w/ secondaryLoadBalancer w/ internet-facing
• Check the subnets for the secondary load balancers: "ext" (public) API Load Balancer's subnets

Actual results:

• Private subnets attached to the SecondaryControlPlaneLoadBalancer

Expected results:

• Public subnets attached to the SecondaryControlPlaneLoadBalancer

References:

•  [1] https://github.com/kubernetes-sigs/cluster-api-provider-aws/blob/main/pkg/cloud/services/elb/loadbalancer.go#L253-L255