The AWS Marketplace provides a "launch with 1-click" button to simplify deployment of the Pulse Secure Virtual Traffic Manager in EC2.
If you accept the Marketplace defaults a new security group is created for you automatically. The security group is fine for single instances of vTM, but attempts to cluster traffic managers associated with this security group will fail.
Prior to clustering traffic managers, modify your security group to open ports 9080 and 9090 for UDP traffic. For more information read the Before You Begin section in the Cloud Services Installation and Getting Started Guide - see vADC Product Documentation