Merge request threads only track changes once

Problem to solve

We use threads in merge requests to ask for changes in code, and sometimes the discussion spans accross several commits.
In this case, the thread correctly tracks the first change (there is a “userX changed this line in version Y of the diff” message with a snippet of the changed code), but subsequent changes are not tracked.
It makes following changes very hard for the reviewer, as they are not informed of changes to the discussed code after the first one.

Steps to reproduce

Create a merge request with some changes
Create a thread on a changed line
Change the line, commit and push
Change the line a second time, commit and push again

The thread will only show the first change, and will not show the second one

Configuration

Threads are set to NOT be automatically resolved when they become outdated.
In our workflow, it is the reviewer responsibility to mark thread as “resolved”

Versions

  • Self-managed
  • GitLab.com SaaS
  • Dedicated

GitLab Community Edition v17.7.1

Is this a bug, or is this the normal way GitLab works ?