Gitlab CI only:changes/except:changes triggers unexpected job

Summary

GitLab CI only:changes/except:changes doesn't work as expected.

I creted a commit with only one file changed and this commit triggered unexpected jobs in the pipeline.

Steps to reproduce

I introduced the following job definition in my gitlab-ci:

build_release-itsdb-gui-job:
  stage: build
  only:
    refs:
      - /^release.*$/
    changes:
      - ItSdb-Gui/**/*
  script:
    - cd $CI_PROJECT_DIR
    - cd ItSdb-Gui
    - mvn $MAVEN_CLI_OPTS -T1C deploy
  artifacts:	
    paths:
    - "*/target/*.war"
    - "*/target/*.jar"
    - "*/*/target/*.war"
    - "*/*/target/*.jar"
    expire_in: 1 hrs
  tags:
    - docker,java,not-privileged

which should trigger only on release branches and it with changes under the path ItSdb-Gui.

Here is the commit content: https://nimb.ws/eb4F3R

And here are the jobs triggered: https://nimb.ws/gQk3Ue

as you can see build_release-itsdb-gui-job was triggered in the pipeline, along with others which shouldn't have.

What is the current bug behavior?

build_release-itsdb-gui-job is triggered when the only:changes should have prevented it.

What is the expected correct behavior?

build_release-itsdb-gui-job not triggered.

Relevant logs and/or screenshots

Here is the commit content: https://nimb.ws/eb4F3R

And here are the jobs triggered: https://nimb.ws/gQk3Ue

GitLab Community Edition 11.8.1