My questions are continuously being down-voted, and nobody is bothering to leave a comment describing why are they down-voting it. In my point of view, my questions are fairly legitimate. I think it is called "serial down-voting", as mentioned here.
I saw three of my questions getting down-voted, although I don't see any reason for it, and them not telling any reason in comments proves it.
Likewise, a couple of my questions were down-voted, and even marked as duplicate of each other, and the down-voting made my reputation fall below 15. I could not even upvote good answers to my questions after that. Yesterday, I flagged those comments and mentioned the reasons when flagging them.
Now I think this is happening again. So please tell me if there is something wrong with them, so that can I fix them? If it's a serial downvoting, please take the proper action.