Website: https://www.payetteforward.com/my-iphone-voicemail-password-is-incorrect-heres-the-fix/
With Visual Voicemail, you can see a list of your messages and choose which ones to listen to or delete. Learn how to set up and transfer your existing voicemail. Create a voicemail password, then tap Done. Enter your password again to confirm it, then tap Done. Select Custom or Default. If you choose Custom, you can record a new greeting. Go to the Phone app, then tap the Voicemail tab. Tap Set Up Now. Enter your password,* then tap done. Record a custom greeting or use the default greeting, then tap Save.

4 hours agoThe process is very simple. You'll just have to click the green phone icon, the same place you make calls, and navigate to the voicemail screen. On the voicemail screen, you'll see a greetings option on the top left. Once you click greeting, you can change it from default to custom and record your custom greeting.
When you reset network settings, all of your iPhone’s Wi-Fi and cellular network settings will be erased. This includes your Virtual Private Network (VPN) settings, your Bluetooth devices, and your Wi-Fi networks — so make sure you write down your passwords first! We do this step because it can be very difficult to track down the exact source of a software problem, so we reset all network settings.