AssignPublicIPv4Address default value in configuration is false. This is an important setting and it allows Fargate task to have outbound network access to pull an image from registry.

For user who don't like to expose public address, they can set to false in private environment. I think it's better to change to true as default. Otherwise, even demo doesn't work here.

See more details in https://aws.amazon.com/premiumsupport/knowledge-center/ecs-pull-container-error/