I'm not exactly sure what the problem is, but if you post a reasonably long post I recommend going into the article to make sure it is all there after you hit submit. I have read a few reports of other users having this problem (one thought they didn't save the post), but I just noticed my most recent article gets cut off halfway through. It definitely wasn't like that when I hit submit as I changed the order of the paragraphs after the article was completed.
Is there a potential bug out there, or just user error?
I noticed it happens when I move cursor around the text while an image gets uploaded. Maybe the same happened to you?
It could be - I actually revised my post a few times because I wanted to change the Category, and didn't upload an image.
Since I've seen it mentioned a few other times now I am guessing there is a bug or a nuance that causes it, not sure what it is though.