Two different voicemail messages, can't delete or change one

[RandySea]

Using Tracfone Verizon on iPhone 13.

In March, I changed my voicemail message to say I'd be out of the country for a month. When I returned, I thought I changed the message to something simple. I can listen to it and it's what I want.

The problem is that the new messaga is only heard by someone calling when my phone is off. I can edit it easily using the usual key presses or menu choices.

But if I am using my Tracfone, (so my line is busy), the voicemail message the caller gets is the one from March. I cannot find any way to edit or delete that message.

I have traveled frequently in the past and had no similar problem changing my outgoing message when I left and came back.

How can I get back to having a single message?