MD is having synchronization issues (i think that's what they said) so things like comments, forums and chapters are not being updated consistently and as a consequence they disappear, they said they were working on it.
One of our database slaves is out of sync with the rest, and your actions on the site may occasionally get sucked into a time vortex. Anything you do is still being tracked properly on our end, it just might not be immediately visible. So if you randomly see chapters uploaded in the past few hours vanish then reappear, this is why.