Action does not trigger when editing PR title or description after a commit message [skip ci] is added

This is my Github Action

name: Bump Version Workflow

on:
  pull_request:
    types: [opened, synchronize, edited]
    branches: [main]

  workflow_dispatch:

jobs:
  get-mulesoft-apps:
    name: get Mulesoft Apps
    uses: VodafoneIS/mulesoft/.github/workflows/get-mulesoft-apps.yml@main

  bump-version:
    name: Bump Version
    needs: get-mulesoft-apps
    runs-on: ubuntu-latest
    container:
      image: ghcr.io/vodafoneis/mulesoft-build-image:main
      credentials:
        username: ${{ github.actor }}
        password: ${{ secrets.GITHUB_TOKEN }}

    steps:
      - uses: actions/checkout@v2
        with:
          ref: ${{ github.event.pull_request.head.ref }}

      - uses: fregante/setup-git-user@v1

      - name: bump version
        run: |
          echo "${{ github.event.pull_request.body }}" | tee pull_request_body
          /scripts/bump_apps_versions.sh -a '${{ needs.get-mulesoft-apps.outputs.MULESOFT_APPS }}' -t "${{ github.event.pull_request.title }}"

As you can see, it is configured to be triggered when opening a PR against main, when pushing new commits to its branch, or editing the PR Title or Description.
I noticed that when I add a commit with message “[skip ci] message” it will no longer trigger actions when editing the PR title or description. I thought the “[skip ci]” feature should prevent only automatic actions to be triggered upon commiting, but it is actually preventing actions that start based on manual user actions, like editing the PR title or description.

In the image you can see that the branch has only one commit and that no action was triggered.
Which is good.

But if I edit the title or the description of the PR, the action will also not be triggered. Seems weird, because editing someting is a manual action. I think [skip ci] should only prevent automated actions from being triggered.

I was expecting the action to start when editing the PR title or description, no matter the content of the message in a commit.

Is it working as designed?