Pull request UI is not updated (real-time or asynchronously) while approving by the reviewer

Summary

Pull request is not updated when gets approved by the reviewer.
Also, when the pull request is set to unapproved by the reviewer, the receiving end receives a notification that the Pull request is approved. (See screenshot)

Steps to reproduce

1. User A raises PR, keeps PR page open in browser.
2. User B (reviewer) opens PR, reviews.
3. User A sees User B's avatar on the bottom right of the PR page indicating User B is viewing the PR.
4. User B(reviewer) clicks Approve on the PR.
5. User A wait several minutes but the PR page never updates to show User B's approval.
6. User A opens the same PR page in another browser window, User B''s approval is shown there.
7. User A closes new browser window, returns to original PR window, approval still not shown.
8. User B clicks Unapprove on the same PR. (Where the bug came in)
9. Within 20 seconds User A sees User B's "viewing" avatar at the bottom right showing the Green Tick overlay. Mousing over User B's overlay reports "User B has approved this PR". However at this point, the PR is actually not approved.

Expected results

• User A's PR will be updated asynchronously (or real-time)
• User A should not received a notification of approved PR while the action is "unapproved"

Actual results

• User A's PR is not updated asynchronously (or real-time)
• User A receives a notifcation of approved PR when "unapproved" action is done by User B(reviewer)

Workaround

Reload the page every time we will check any approvals