I have two repositories and both are in same project of ADO:
one is at the top level (It also include pipeline yaml), and the other is defined as a submodule. I want to trigger a pipeline whenever an update is pushed to either the main repository or any of the repositories declared as resources(submodule mentioned here).

I tried below code but it only trigger on changes in self or if i run manually.

trigger: 
- main

pool:
  name: 'myselfhostedagent'

resources:
  repositories:
  - repository: sub_repo
    type: git
    name: test/sub_repo
    ref: master
    trigger:
    - master

steps:
- checkout: self
- checkout: sub_repo
- script: |
      echo $(Build.Repository.Name)
      echo $(Build.SourceBranch)
      dir $(Build.SourcesDirectory)

Troubleshooting:

1. I defined self trigger to none but no success
2. I created pipeline in sub_repo and it getting trigger properly
3. As per docs
   “If a change to any other repository resource triggers the pipeline, then the latest version of YAML from the default branch of self repository is used.”
   I verified that my self repo has defined main as default branch.

Any tips to resolve this or any way to verify from logs that as soon as i do push in sub_repo how AzureDevOps handle it.