iPhone SE is not receiving voicemail notifications

I got an iPhone SE (iOS 13.6.1) about 2 weeks ago and have not been able to get notifications that I have a voicemail. I will see a missed call notification on the lock screen but only if I open the Phone app and see a badge on the voicemail icon do I know there is a voicemail. (Notification Center also does not indicate there is an unheard voicemail.) The phone app has notifications fully enabled and cellular data is on. Can anyone offer a solution? Thanks