"Resolve thread" button doesn't appear when you reply to a comment

Summary

"Resolve thread" button doens't appear when you reply to a comment in a merge request.

Steps to reproduce

  1. Open a merge request
  2. Find a comment
  3. Leave a reply under that comment
  4. The button "Resolve thread" does not appear, you have to refresh the page to fix this

What is the current bug behavior?

"Resolve thread" button doesn't appear when you reply to a comment, unless you refresh the page.

What is the expected correct behavior?

"Resolve thread" button should appear immediately after you reply to a comment.

Relevant logs and/or screenshots

The following image is from right after I replied to a thread. It doesn't have the "Resolve thread" button.

Screenshot_2020-07-28_Add_a_resource_group_for_pages___1037____Merge_Requests___GitLab_org_GitLab_Docs

After I refresh the page, the button appears.

Screenshot_2020-07-28_Add_a_resource_group_for_pages___1037____Merge_Requests___GitLab_org_GitLab_Docs-b

Output of checks

This bug happens on GitLab.com

Edited by Achilleas Pipinellis