On Amazon AWS we offer tiered instances that should be billed and licensed through Amazon AWS directly. These are recognizable from the (xx connected devices) in the title of the offering on the Amazon AWS Marketplace. These should be automatically licensed within seconds after startup of Access Server. If it doesn’t get licensed automatically, then it falls back to an unlicensed state where only 2 connections are allowed.
The most likely problem is that contact with the software licensing server was not possible. Make sure that the server can reach awspc1.openvpn.net on port TCP 443. There are also backup licensing servers available (awspc2.openvpn.net, awspc3.openvpn.net, awspc4.openvpn.net). Most commonly the issue is that people launch the AWS Marketplace OpenVPN Access Server offering while specifying custom security groups settings that block this access, or set up such security group settings afterwards and block this access.
More information on IP addresses and ports of our licensing servers for Amazon AWS is available in the troubleshooting guide for OpenVPN Access Server AWS tiered instance licensing.