Notification that mailbox is full

[Andiatc]

My iphone 11 pro max  gives me a notification that my mailbox is 97% full, and my clients can't leave a message because they get a message that my mailbox is FULL. But it's not. I have very few saved messages, and have deleted all "deleted" messages. How do I fix this problem? 

[HausOfThunder]

I had the same problem with the 11 Pro Max so I called XM Customer Service. They had me call my voicemail directly and there were lots of saved and new voicemails that were not showing up in my visual voicemail.