Circle-ci: No workflow when I set filters to only tags and ignore all branches

I’m trying to run a workflow only on tags, but I’m getting no workflow
And when I remove ignore branches, it runs on every branch and tag.
Do I miss something? Or what exactly can I achieve with this usecase?
This is a screenshot, and I’m expecting the workflow to run on instable-2.7.31.
Screenshot- noworkflow

Thanks.

My .circleci/config.yml

only-deploy-unstable: &only-deploy-unstable
  context: Unstable-context
  filters:
    tags:
      only: /^unstable-.*/
    branches:
      ignore: /.*/

version: 2.1

jobs:
  build_unstable:
    docker:
      - image: docker:20.10.8
    environment:
      DOCKER_IMAGE_BASE_URL: **********
    steps:
      - checkout
      - setup_remote_docker
      - run: apk update
      - run: apk add git
      - run: docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
      - run:
          name: build and push unstable docker image
          no_output_timeout: 15m
          command: |
            export TAG_NAME=$(git describe --tags --abbrev=0)
            echo ${DOCKER_IMAGE_BASE_URL}:$TAG_NAME
            docker build  --build-arg STAGING=test --rm -t $DOCKER_IMAGE_BASE_URL:$TAG_NAME -t $DOCKER_IMAGE_BASE_URL:latest .
            docker push $DOCKER_IMAGE_BASE_URL:$TAG_NAME
            docker push $DOCKER_IMAGE_BASE_URL:latest
  deploy_unstable:
    docker:
      - image: docker:20.10.8
    steps:
      - checkout
      - setup_remote_docker
      - run: command -v ssh-agent >/dev/null || ( apk add --update openssh )
      - run: eval $(ssh-agent -s)
      - run: ********************

workflows:
  # build unstable-version 
  
  build_and_push_unstable:
    jobs:
      - build_unstable: *only-deploy-unstable
      - hold:
          <<: *only-deploy-unstable
          type: approval
          requires:
            - build_unstable
      - deploy_unstable:
          <<: *only-deploy-unstable
          requires:
            - hold