Azure Pipeline Value of variable gets lost when accessing second time during the propagation between the stages

I am trying to implement a pipeline where the first stage sets the value of a variable and all the consecutive stages access this value.

Following is my YAML. Here Stage ST1 is setting value of Variable VAR1. I am able to access the value of the VAR1 in ST2. However, after ST2, when ST3 runs, this value gets lost and in ST3 I get the empty value.

Is there any way to preserve this value throughout the stages?

Thank you,

stages:
  - stage: ST1
    jobs:
      - job: 
        steps:
        - task: 
          name: TASK1
          inputs:
            script: |
              echo "##vso[task.setvariable variable=VAR1;isoutput=true]Hello"

  - stage: ST2
    variables:
    - name: VAR1
      value: $[stageDependencies.Build.Build_Artifact_Job.outputs['TASK1.VAR1']]   
    jobs:
      - job: 
        steps:
        - task: 
          inputs:
            script: |
              echo "$(VAR1)" # Prints "Hello"

  - stage: ST3
    variables:
    - name: VAR1
      value: $[stageDependencies.Build.Build_Artifact_Job.outputs['TASK1.VAR1']]   
    jobs:
      - job: 
        steps:
        - task: 
          inputs:
            script: |
              echo "$(VAR1)" # Prints Empty String

Check the documentation there is information that: Output variables are only available in the next downstream stage. If multiple stages consume the same output variable, use the dependsOn condition.

Below is a working example.

trigger: none

pool:
  vmImage: ubuntu-latest

stages:
  - stage: ST1
    jobs:
      - job: Build_Artifact_Job
        steps:
        - task: CmdLine@2
          name: TASK1
          inputs:
            script: 'echo "##vso[task.setvariable variable=VAR1;isoutput=true]Hello"'
         
        
  - stage: ST2
    dependsOn: # Use dependsOn to get access to output variable from the stage
    - ST1
    variables:
    - name: VAR1
      value: $[stageDependencies.ST1.Build_Artifact_Job.outputs['TASK1.VAR1']]   
    jobs:
      - job: 
        steps:
        - script: echo "$(VAR1)" # Prints "Hello"

  - stage: ST3
    dependsOn: # Use dependsOn to get access to output variable from the stage
    - ST1
    - ST2
    variables:
    - name: VAR1
      value: $[stageDependencies.ST1.Build_Artifact_Job.outputs['TASK1.VAR1']]   
    jobs:
      - job: 
        steps:
          - script: echo "$(VAR1)" # Prints "Hello"