Voicemail password not saving

I recently got a new iPhone 15 base model with my provider. Two days ago. Everything transferred over, but with my voicemails it says I have one so I want to check. When I go to check it tells me to “set up voicemail”. I press it and it says “enter a voicemail password”. I’ve tried tons of different ones and putting it in twice like asked. It then says “saving password”. It then takes a while and says “error”. Please help.