All pull request comments get outdated when pushing new changes (Mercurial repo)

I opened a pull request today, added a number of comments to a number of files and then pushed a change to one of the files. While I did expect comments on this specific files, on lines that had changed, to be marked as outdated, I did not expect all my comments, on all files, to become outdated (and therefore hidden). This is terribly annoying as it means reviewers now need to open the Activity tab to see the old comments, instead of having them in line with the code. Am I missing something or is this a bug?

I'm aware of this similar issue, but my scenario is slightly different in that I did make a change to one of the files (although it may be the same root cause?).

Here's a link to the pull request (it's private, but hopefully you can access it).

Cheers,

Remi