Job can run successful without executing all script commands

I am using GitLab CI/CD with Docker to create Docker images, in this case to create a image of my application and publish it to a container registry.

The problem: Gitlab ci tells me the job succeeded but only 1 command was executed “docker build …” and the command “docker push …” was not executed.

build:
  variables:
    <<: *app-variables
  stage: build and push image
  before_script:
    - docker login $DOCKER_REGISTRY -u $DOCKER_AUTH_USER -p $DOCKER_AUTH_PASSW
    - cd $CI_PROJECT_DIR/apps/$DOCKER_APP_FOLDER
  script:
    - |
      docker build --target=buildimage -t $DOCKER_REGISTRY/$DOCKER_REPO/$DOCKER_APP_FOLDER/build:$CI_COMMIT_BRANCH .
      docker push $DOCKER_REGISTRY/$DOCKER_REPO/$DOCKER_APP_FOLDER/build:$CI_COMMIT_BRANCH

I already tried to change script command to the bellow code but has the same behaviour.

script:
    - docker build --target=buildimage -t $DOCKER_REGISTRY/$DOCKER_REPO/$DOCKER_APP_FOLDER/build:$CI_COMMIT_BRANCH .
    - docker push $DOCKER_REGISTRY/$DOCKER_REPO/$DOCKER_APP_FOLDER/build:$CI_COMMIT_BRANCH

I don’t know if it is related but the build of the image can take some time ~30min.
I tried with simpler Dockerfile and the command docker push worked.
I think the problem is related with my Dockerfile somehow.

The result of job:

Any suggestions how to solve?