Voicemails delayed on iPhone

Please contact your Carrier as VoiceMail is a carrier-specific feature --> Check your voicemail on iPhone - Apple Support

You may try some of these steps, please check after each step...

The delayed Voice Mail message typically indicates an issue with the settings on your iPhone. There are several potential reasons for this error, and here are some troubleshooting steps you can follow to resolve the problem:

1. Ensure that your iPhone has a stable internet or cellular connection. Voicemail services may require a data connection to function correctly.
2. Check if there are any carrier settings updates available for your iPhone. Carrier updates can sometimes resolve voicemail-related issues.
3. Contact your carrier's customer support to ensure there are no known issues with their voicemail services in your area.
4. If you have call forwarding enabled, try disabling it to see if it resolves the voicemail problem. Go to Settings > Phone > Call Forwarding and turn it off if it's enabled.
5. Sometimes, a simple restart can resolve temporary software glitches. Turn off your iPhone, wait for a few seconds, and then turn it back on.
   1. Restart the device. That's it.
   2. Still not solved --> Force restart iPhone - Apple Support
6. If the issue persists, you can try resetting all settings on your iPhone. This will not erase your data but will reset all personalized settings to their default values. Go to Settings > General > Transfer & Reset > Reset > Reset All Settings and confirm the action. Note that you will need to reconfigure your settings afterward. All settings—including network settings, the keyboard dictionary, the Home screen layout, location settings, privacy settings, and Apple Pay cards—are removed or reset to their defaults. No data or media are deleted.
   1. Reset All Settings: Return iPhone settings to their defaults - Apple Support:- Return iPhone settings to their defaults
   2. You can return settings to their defaults without erasing your content.
   3. If you want to save your settings, back up your iPhone before returning them to their defaults. For example, if you’re trying to solve a problem but returning settings to their defaults doesn’t help, you might want to restore your previous settings from a backup.
7. Make sure you have the latest updates installed.
   1. Update Over-the-Air (OTA) —> Update your iPhone or iPad - Apple Support (IN)
   2. Update using iTunes/Finder —> Update your iPhone, iPad, or iPod touch - Apple Support (IN)

If none of the above steps resolve the issue, it is recommended to reach out to Apple Support or visit an authorized service center for further assistance. They can provide specific guidance based on your device model and iOS version.