Agents running reporting internal hostname on EC2 instances

We are running TeamCity and a few agents on static Windows AWS EC2 instances. Until recently, the agent pages were showing the external hostname and IP address. Since upgrading to 2017.2, they are showing the internal versions. Everything is working fine, it's just an annoyance to have to log into the AWS console to find the external info. Guessing we misconfigured something in the upgrade but we no longer have that old server/agent configs available to compare.