Just called my home phone 4 times. I did not answer. After 3 rings it disconnected and then immediately called again...a definite sign this is robo calling.
These calls seem to go in cycles. Will not get any for a week and then they begin with 3 to 4 a day for a few days. I never answer any of them and immediately block the number for future calls. If you don't identify yourself, then I am not obligated to answer.!