I thought it used to be working perfectly, but it's fallen off since, I guess, the start of this year.
I didn't receive notifications for any of the replies to this comment, except for JokerPullsBoner's (interesting to note, all of the comments I didn't receive notifications for were just embedded videos)
Then I didn't get a notification for the reply to this comment: https://knowyourmeme.com/comments/6113534
maybe the bot chokes whenever any embedded media is included in the reply? I'm pretty I used to get replies with embeds but I can't remember when.