Some PR comments do not link to the full PR
In News and Notifications, I've seen several instances of comments on pull requests that don't show a PR number, and when I tap on it, it sends me to a list of all open PRs.
I'll see if I can post a screenshot here, but if not, basically the text of the item is something like:
user has commented on pull request in project/name (etc.)
Note the double space between "request" and "in".

Great catch. Very odd though. I'll look into this and fix in the next release.
I think I see what the issue is. The comments that don't show the PR # are actually comments on a commit that's part of the PR.
Issue still exists

Issue still exist by now, i experienced that as well.
Issue still exists as of Jan. 2020.