Why do I have a second voicemail notification after listening to the voicemail?

[ahwdvm]

Help - Second Voicemail Notification after Listerning to the Voicemail

Someone calls and leaves a voicemail message and I get a notification, both a notification sound and an icon at the top of the screen and an icon on the screen. I swipe and remove the notice on the screen and the icon at the top of the screen, call in and listen to my message, delete it, and as soon as I hang up, I get another message notification for the voicemail, both a sound and the icon and notice on the screen. Why am I getting this second notification after I have already listened to my VM, deleted it and hung up? This has never happened on my other phones and it is annoying. Any help is appreciated.