I woke up today to a few emails from YouTube telling me I had received some comments so I logged in to answer then I noticed I had comments on there from a week ago but I had no notification and they were not in my inbox/comment section. So I have had to check every video one at a time to check for new comments.
So I'm sorry if my reply was late and if I still haven't replied to your comment/question please inbox me or leave the message again :)
Sorry again!