Pipeline indicating failure when work flow rule bypasses child pipeline

GitLab CI/CD
#1

I have a mono repo. So I created a parent pipeline

admin server build:
  trigger:
    include: "admin_server/child_gitlab-ci.yml"

default server build:
  trigger:
    include: "default_server/child_gitlab-ci.yml"

faqbot server build:
  trigger:
    include: "faqbot_server/child_gitlab-ci.yml"

Then in each application dir I have this child pipeline.

# only run if there are changes..
workflow:
  rules:
    - changes:
        - admin_server/**/*
      allow_failure: true

Everything works as expected however, if there is a application that doesn’t have any changes… it marks it as failed. The error message from gitlab says it is due to the work flow rule being false. (no changes). Can you help with correcting this behavior. I need the email notifications not to be false alarms.

Thanks
Brad