How does Azure DevOps identify linked workitems during pipeline (Azure DevOps YAML)?

I believe it is supposed to get only the workitems linked to new commits (i.e. commits which were not included in a previous pipeline)

However, it sometimes seems to link all work items. But this does not always happen. I did not manage to identify the pattern yet. But I noticed that when I do a change in the pipeline YAML, it seems to trigger this behaviour that links all work items again (even if they where linked to a previous commit and not to newly included commits).

Updated to include additional information

This is my build pipeline YAML

name: 03.01.00$(Rev:.r)
pool:
  name: Hosted VS2017
  demands:
  - msbuild
  - visualstudio
  - vstest

steps:
- checkout: self
  clean: true
  persistCredentials: true

- task: NuGetCommand@2
  displayName: 'NuGet restore'
  inputs:
    restoreSolution: MySol/MySol.sln

- task: VSBuild@1
  displayName: MySol/MySol.sln
  inputs:
    solution: MySol/MySol.sln
    vsVersion: 15.0

- task: WorkItemUpdater@2
  inputs:
    workitemsSource: 'Build'
    workItemType: 'Task,Bug'
    updateAssignedTo: 'Never'
    updateFields: 'Microsoft.VSTS.Build.IntegrationBuild,v$(Build.BuildNumber)'

- task: VSTest@2
  displayName: 'VsTest - testAssemblies'

Pipeline settings:

Processing od new run requests: Enabled

Automatically link work items included in this run: checked & dev branch selected

Triggers:

Override the YAML continuous integration trigger from here: checked

Enable continuous integration: checked

Batch changes while a build is in progress: unchecked

Branch filters

Included dev branch + another feature branch

Path filters

None