If you are testing out AWS and Pexip Infinity, you may shutdown your VMs to save some money when you are not testing.
However, when you power back on the VMs, Amazon may assign different public IPs to your virtual machines. If that is the case, you will need to update your DNS A records and also the static NAT configuration in Pexip of the Conference Node(s).
You will need to head to your EC2 Management Platform and obtain the new public IP addresses.
Grab a coffee whilst DNS and the Conference Node updates and you should be back in business.