What carrier do you have? AT&T has started a program (free) that can somehow check numbers, no doubt on a huge database, very quickly and make an 'educated' guess about their validity.
I'm not aware that the iPhone (or any other brand) itself can do much more than check your own list of blocked calls. (Not being aware of something is often a 'state' I visit, however!
) In that case, I don't think it gives any direct notifications and may just hang up after a shorter ring. That
would generate a "Missed call" alert. It is possible to have "alerts" repeated on your Apple hardware, I guess.
We can only hope that these systems do get smarter and less obnoxious!
If you have updated to the newest iOS/macOS, you may also have some phone features/functions I don't. Good to see you've got some help, no matter where it comes from!
