Changing approvers on an issue with multiple approval steps appears to duplicate the approval history in the Customer Portal for earlier approvals

Issue Summary

This bug only affects requests that go through more than one approval status and use the same field for approvers. In later approval steps, removing an approver from the approvers field after Approved Step 1  and adding a new approver ; will cause that approver's field to duplicate and be seen in Approval Step 2 as well as Approval Step 1 . This is only affecting the Customer Portal; the Agent View is unaffected and will show the correct history.

Steps to Reproduce

1. Create a Workflow or Modify the Approvals Workflow to Include a 2nd Approval Step.
2. Ensure the Same Approvers Field in used for Approve Step in both the Approval Status ( Select All Status can Transition to Speed up the process )
3. Publish the Workflow and then create a test ticket from the Portal ; Add a Approver ( Example : ABC ) 
4. Login as ABC and Approve - > Transition to 2nd Workflow Steps
5. Manually ; Clear Approver Field and Replace it with another User ( Example XYC ) 
6. Login as XYC and Approve. 
7. Once approve login in customer portal and you will see that XYC is also seen in Approval Step 1.

Expected Results

In Customer Portal , Each Approval Step should show only the Approvers who approved in that Step and not the Approvers of next Approval Step

Actual Results

We see Approvers of the Second Approval Step Populating in First Approval Step in the Customer Portal , Screen Shot attached for Reference 

( UserAtlassian is Added as a Approver in Approval Step2 , but is populating in Approval Step 1 as well )

Workaround

Use Separate Approver Custom Fields for Each Approval Step