I made a similar thread about missing word notes recently, but I noticed the replies for the most popular Question Corner comment on my profile have suddenly disappeared. I had around two replies and liked to reread them from time to time, but they vanished recently. I doubt the users manually deleted their comments months after publishing them. Is there no way of knowing what happened to the messages? (I suppose it could be a server-related storage issue...)
No storage issues - I don't delete user content because of space, ever. Users can delete their own stuff, of course.
If you'd like to point me towards your specific sentence, I can see if there are any hints floating around on this end.
I don't remember enough of the specifics of the comments to replicate them word-for-word, but I do know one of the user's comments was written in Japanese and talked about how their sensei went to Japan and brought back candies from a conbini. (This was in response to my "コンビニの食品です" Question Corner answer.)
Edit: I figured out what's happening, and the comments have not been deleted. The comments are just invisible on my profile page. If I view my comment on the "My Writing" tab, the answers are still there.