The AWS CLI v2 tries to use a client-side pager by default. Then, in a lot of cases, it'll wait for interactive input before returning 🤷🏻♂️. You can "use the --no-cli-pager command-line option to disable the pager for a single command use" (or use any of the other options described there).
Some SO questions around this:
- https://stackoverflow.com/questions/61541839/aws-cli-2-cant-update-service-use-cli
- https://stackoverflow.com/questions/63518991/aws-ecs-create-service-waits-for-user-input-while-showing-output-on-console
