A company has introduced a new security policy that mandates scanning all traffic from AWS instances within its VPC for security policy violations, enabling the blocking of access to and from specific IP addresses. To comply, the company has set up Amazon EC2 instances in private subnets as transparent proxies, installed approved proxy software on these instances, and configured route tables to route traffic through these proxies. Additionally, security groups adhering to the security policies have been assigned to these EC2 instances. Despite these measures, internet traffic from the EC2 instances in the private subnets is not being correctly routed. What action should a solutions architect take to rectify this issue?