Voicemail Troubles

My iPhone XR with iOS13.7 is having multi day delays in receiving voicemails. I have tried closing the app, restarting the phone, and switching cellar data and wifi data off & on. So far, no luck. I also tried changing my outgoing message to ask callers to text rather than leave a message. I was unable to save the new recording getting an error 1035. Some of these measures allowed one known vm to come through but not others.