I have asked other members of the production team to put in comments in the XD prototype.
First of all, I get a response from them after they have left comments, that they are not sure if they were posted so that I will receive them, or that they will even be stored somewhere.
Secondly, when I go and see the comments, they only appear for a split second on the prototype, and then vanish. System says that there are no comments. I receive an email, and see those comments in notification bar, but clicking on them does not give me the context.

Conclusion: You should make better UX for lodging comments, and give users response that they have left something and that the recipient will be notified. Then there must be a bug, as linking comments does not seem to work. Check, how Invision does this - it works well...