Is there a way to ask about the reasons why some posts went missing

They're probably deleted.

They're deleted for various reasons, of course those reason you can find it yourself but from my observation a post is usually deleted because the subject in question is underage.

Be more specific, please. Were all the images by a single artist? If so, they may have been removed due to a takedown request filed by the artist who created them.

Were all the missing pics of the same character? Did the missing pics have any other common quality such as featuring a particular kink or fetish?