Empty line causes: ** (Mix) mix format failed due to --check-formatted

I use Elixir 1.15.7 OTP 26 both in development (Windows) and on a GitHub runner (ubuntu-latest).

The GH Action fails on: mix format --check-formatted.

         |
 46  46  |          name
 47  47  |          organizationId
 48     -|  
     48 +|
 49  49  |          ... on Comment {
 50  50  |            text
         |

The code looks like this:

  @query """
  mutation ($organizationId: ID!, $type: ArticlesType!, $names: [String!]!) {
    createArticles(organizationId: $organizationId, type: $type, names: $names) {
      __typename
      ... on CreateArticlesSuccess {
        articles {
          __typename
          name
          organizationId
  
          ... on Comment {
            text
          }
        }
      }
    }
  }
  """

It seems that the fail is due to an empty line, but when I run the exact same command in development mix format --check-formatted there are no changes.

Any idea why this happens?

C:\data\projects\foo>elixir --version
Erlang/OTP 26 [erts-14.1.1] [source] [64-bit] [smp:12:12] [ds:12:12:10] [async-threads:1] [jit:ns]

Elixir 1.15.7 (compiled with Erlang/OTP 26)

GH Actions config:

    runs-on: ubuntu-latest
    name: Test on OTP ${{matrix.otp}} / Elixir ${{matrix.elixir}}
    strategy:
      # Specify the OTP and Elixir versions to use when building
      # and running the workflow steps.
      matrix:
        otp: ['26.0']       # Define the OTP version [required]
        elixir: ['1.15.7']    # Define the elixir version [required]