I have a GitHub workflow

jobs:
  timeout-minutes: 20
  deploy:
    runs-on: ubuntu-latest
steps:

  - name: Checkout
    timeout-minutes: 5
    uses: actions/checkout@v2.3.4

  - name: Hugo setup
    timeout-minutes: 5
    uses: peaceiris/actions-hugo@v2.5.0

  - name: Build
    timeout-minutes: 15
    run: hugo --minify

If Checkout and Hugo setup both consume 5 minutes, what will happen when the Build step runs to minute 12?

I thought the whole job will be cancelled when the Build step runs to minute 10 in an ideal state, it can’t run to minute 12.

But GitHub supports told me It gets canceled after 5 minutes.

5+5+12+5=27 , it exceeds the timeout minutes of the job, why? Thank you.