I have tried several free apps to block calls. One, Call Protect, was pretty good. I want an app that lets me block an entire area code or exchange. I get a lot of calls that spoof the area code and exchange to be the same as my own. However, these apps no longer work on my iPhone! I do not have an answer why yet, but apparently with IOS 14 the ability to enable 3rd party call filter apps has been removed. Has anyone else seen this?
If you go under Settings / Phone / Call Blocking and Identification there used to be a list of installed call blocking apps and a slide button to enable or disable them. Now there is a single option called Carrier Call Identification and a slide button to "Silence Junk Callers". There is no control over this. It is on or off. You can still block numbers but you have to use the entire number. No more blocking partial numbers as some apps allow. If this is a permanent feature of the iPhone this will be my last iPhone.