The block actually does work. It's not a hard software block. It just turns off the ringer. The robo calls pause and wait for a pickup. If you pick up, then more calls.
You have to not pickup, select the recent number from the call log and block it on your phone.
They do call from the same numbers and quite often, If I goto the recent call list on my cell phone, I can see several of the blocked icon next to the number. It blocks(turns off the ringer) for several calls each day. When my phone rings I look at it, and if I don't pick up I block the number. If it's an important caller they can leave a message. But robo cannot leave a message and solicitors rarely do. At first it's clumsy to block, but I know the clicks now and am pretty fast at it. It's a maintenance routine now!
The block procedure has reduced my rings per day.
j