Mobile data problem on iPhone 11 Pro

Hello Colcol91,

Thanks for sharing the steps you've completed, and answering the questions so we can quickly guide you forward. Next, we recommend the following:

• Open Settings > General > VPN. If a VPN is installed - even if it's turned off - uninstall or delete the VPN app as well as any security software.
• Open - Settings > General > Profile. Is there a profile installed that is not required by your cellular carrier? Consider removing the extra profile.
• Check Settings > Cellular > Cellular Data Options and make sure Low Data Mode is not enabled.
• Reset Network Settings from Settings > General > Reset, and test the connectivity.

Note: This also resets Wi-Fi networks and passwords, cellular settings, and VPN and APN settings that you've used before, so be sure to have the credentials available when you try to reconnect.

If you complete these steps and continue to encounter an issue, then Contact Apple Support for further assistance.

All the best!

Greetings Colcol91,

Welcome to Apple Support Communities. We're glad you're here, and it will be our pleasure to assist you.

We understand from your post that:

1. You must toggle Airplane Mode on, then off again, after making or receiving phone calls on your iPhone 11 Pro Max to access cellular data.
2. You've contacted your cellular carrier to check their provisioning, and inserted a new SIM card, but the issue persists.
3. You've also reset the device to factory settings, and tested cellular data access using a SIM card from another carrier.

You've done extensive troubleshooting so far, and we thank you for sharing those particulars.

We recommend the following steps to resolve this as quickly as possible, :

• If you see No Service or Searching on your iPhone or iPad or if you can't connect to cellular data.
• Should you need to "Contact your carrier" as directed in the link above, then we want you to know "Issues with your carrier or account might affect your service. Contact your carrier to:
  • Verify that your account is active and in good standing.
  • Make sure there are no outages in your area.
  • Check that your device isn't blocked from receiving cellular services and is set up with the right data plan."
• Open this guide to Check the cellular data usage on your iPhone and iPad and confirm that your settings are configured to allow you to use the apps and features you desire when Wi-Fi is not available. Consider if the issue is related to a specific app or if all apps are affected.
• We also suggest you View and edit your Access Point Name (APN) on your iPhone and iPad, and review these details with your carrier.

Let us know what you experience after completing these steps, and we'll guide you forward. If the issue continues, please tell us:

1. Which iOS version is installed. Open Settings > General > About > Software Version.
2. If you completed each step in the links above, in the order they appeared.
3. Are all apps and features affected? Were you able to check Settings > Cellular Data?
4. Do you see 'No Service' or 'Searching' at the top of your iPhone display when you cannot to a cellular network or cellular data?
5. Any additional steps you have completed.

Warmest regards!