Reply by e tag doesn't tag OP Fediverse-side
(this is probably not a bug)
If I post something on the Fediverse side, and then reply to it from Damus, the reply refers to the original message using a reply and/or root e tag. It will not have a p tag, unless the text itself says "@ you".
The Fediverse note has its inReplyTo set correctly, and if you go to the thread in Mastodon it renders correctly. But there's no notification.
This seems intentional. Nostr clients should probably explicitly tag someone if they want them to be notified.