an update from another user I am following is not on home page or come through device updates

This update is not showing on my home page or other peoples feed for that matter it says under it it's a reply but it doesn't begin with @username and I'm pretty sure I have gotten updates on my home feed that were @replies to other people from him. But anyways how could it be a reply without that beginning plus it doesn't even sound like a reply or related to what he was "replying" to

EDIT: I just found out the person he was replying to wasn't even aware it was a reply to them for days