Trying a change of what I do when receiving bogus or unidentified calls.
I put a Telezapper in line and for it to work, you have to pick up the phone and say NOTHING for several seconds.
It emits a tone that tells the autodialer that your phone # is not a working number.
Scammers make money by talking to enough people to find a naive victim to run their con. They also make money be selling valid phone numbers to other scammers. They don't want to waste time calling numbers that are not working, so given some time this should seriously decrease the number of bogus phone calls I get.