Auto Import does not work

I recently migrated from Eclipse STS to IntelliJ IDEA.

But I am having trouble having class dependencies imported. I have added unambiguous imports on the fly" in Settings > Editor > General > Auto Import. But still, it doesn't work.

On top of that, it doesn't highlight missing import  (or other compilation errors) on the fly, I have to wait until I compile to see it that something was wrong.