Unable to leave voicemail messages

Hello, again, everyone. I’m back with another question for those of you who understand tech issues, because I do not. I live in the USA, use a pre-loaded Samsung S9, and have service through T-mobile.

I’ve recently realized that I can no longer leave voicemail messages, though I can still receive them. When I call someone and they don’t answer, I hear their greeting and the beep, but when I talk, nothing is recorded. Instead I hear a spoken pre-recorded message stating the “nothing has been recorded”. This has happened with other T-mobile users and people who may/may not use T-mobile. Any ideas what’s causing this and how to fix it?

Regain your privacy! Adopt /e/ the unGoogled mobile OS and online servicesphone

This sounds like another VoLTE issue to me. Think of it as a mathematical equation:

Spotty/Missing 3G + Lack of Voice Over LTE = Voices Don’t Get There

Have you also experienced some calls where the other person picked up but could not hear you talking? That happened to me sometimes when I had T-mobile service, but not a VoLTE-enabled phone.

Yep, I suspected that. AT&T is looking better all the time. Thanks for the reply.