Rancher pipeline runScriptConfig fails for container built in pipeline

I setup a rancher pipeline where I build a container image, would like to run some tests in it, and finally deploy it. I am just not able to get the test stage to run.
I see that the containers get provisioned when the pipeline run is initialized and the container for the test step remains in unready state. If I look into the logs of the local registry I see 401 followed by 404 errors.
I am wondering how the stage can even be provisioned while the first step wasn’t done (do I get this conceptually wrong?), or where to look for credentials (if this is really the problem)?

Would be very thankful, if someone could point me in the right direction!

This is my pipeline definition

  - name: build image
      - publishImageConfig:
          dockerfilePath: ./Dockerfile
          buildContext: .
          tag: my/project:${CICD_GIT_BRANCH}.${CICD_GIT_COMMIT}
  - name: test
    - runScriptConfig:
        image: ${CICD_LOCAL_REGISTRY}/my/project:${CICD_GIT_BRANCH}.${CICD_GIT_COMMIT}
        shellScript: ./run_my_tests.sh
  - name: deploy
      - applyYamlConfig:
          path: ./pipeline/deployment.yml