Proof comments inconsistently showing up in Updates: Anyone else seeing this or know of settings that might prevent them appearing on one project vs another?

We are getting user feedback that Comments made in a Proof are not always making it into the Updates tab. For instance: I can see the single comment made on V1, and none of the comments make on V2.

These comments exist in both the Proof itself and the Print Summary. It's just that they are not consistently making it to the Updates tab.

This issue has been reported as fairly recent: I don't think it's related to the problems some of us had with late notifications a few weeks back, but the timing was such that I'm simply pointing it out if it helps shake out a root cause.