silence unknown callers DOESN'T WORK for Recents

"Silence unknown callers" is turned ON on my iPhoneSE 16.6.1. Just now, I got a phone call from some company I left a message with a few days ago, who I was no longer interested in. NOT in my contact list, but in my Recents list. So "Silence Unknown Callers" DOES NOT SILENCE numbers that are in your Recents list, even if they aren't in your Contacts list. Apple thinks that, gee, if you called them, you MUST want to hear from them! That is, if they are in Recents, they are "known" to you. In some circumstances, that might be justifiable, but in others not. But I want calls silenced from ANYONE not in my Contacts list. Is there a way to do that? Yeah, I could just always clear my recents list, but that's a pain.