Adding to Blacklist

Been trying to add a number and it won’t allow it. It’s telling me wrong format.

Examples they give are:

555-555-5555 or 5555555555

Tried both. Neither work.

What am I missing?

If you are still having issues, try a different browser such as Firefox.

Why can’t we add directly to Blacklist a number from “VoiceMail/In Box”? … like the set up in “Call Logs”?