Visual voicemail not working

iPhone 7 Plus

Verizon

iOS version 13.3

On my iPhone - Phone - voicemail, it shows 3 messages but apparently I have 7.

So when I dial *86 and then enter my password, it says 'you have 7 new message'.

I tried leaving myself a few messages (from different phone numbers), and none of them appear on my iPhone under voicemail. But all of them are available when I dial *86.

I already tried Verizon support but they weren't of much help. I've already taken the following steps:

1 - Restarted iPhone

2 - turned on airplane mode, then off

3 - Reset network settings

4 - turned cellular off - then on

Any other suggestions?

Thanks