Why do I suddenly need a password to access my voice messages on iPhone 11?

All of a sudden, my iPhone 11 is requiring a password for retrieving voice messages. I've never needed a password and don't want one. All answers I've found say the issue lies with my carrier (Consumer Cellular), but why all of sudden? My carrier has never mentioned needing a password, and it says nothing about it on its website. The only thing I've done recently is set up a greeting. The problem started a few weeks later. I tried entering a password, but it had to be so long I couldn't remember it. I've tried to reset it but always get a "voicemail is not available" response. Is there any way to disable the whole password thing?