Project CI/CD variables scope dropdown missing

I have a project on gitlab.com which has a .gitlab-ci.yml file with a job containing an environment as follows:

staging-deploy:
  stage: staging-deploy
  script:
    - ./deploy-staging.sh
  when: manual
  environment:
    name: staging

All pipeline steps run fine for the project after adding the environment. However, when I go to Settings > CI/CD > Variables, I am not seeing the “staging” environment under the scope option.

All I see is this:

Is there an issue somewhere with my project or am I mis-understanding what the “Scope” column is for?