it's more like an intentional/working as intended feature with the
pages system (which is what it is based on and was there before that Load More feature
introduction/the default one).
Since, the Load More is a different (and newly introduced) feature and doesn't have anything to do with that X-of-X count at all, so it doesn't update that in real-time.
these two systems are conflicting with each other as both serve the
The best option would be to remove one of them, or adjusting so that both work together with each other.
I'd recommend keeping the pages system as it was before/removing the
Load More one.
The pages system is quite handy and accurate where we have a lot of posts/submissions than the Load More (for instance, this thread — you can go to an X page and literally find the post you are looking for quickly rather than having to keep clicking the Load More all the way just to find that specific post, if you get my point).