when using dy in a command block, the command does not work

I KNOW THIS ISSUE HAS BEEN POSTED BEFORE

I have searched for an answer but have not found one!

It seems as if that the moderators do not want to deal with it as I have seen other issues similar to this one have been 'resolved' as they have been duplicates... of each other?

Two issues have been marked as a duplicate because they duplicate each other, which is impossible.