Q: Mobile data not working after upgrade

Hello there, Effi.

It sounds like you unable to connect to cellular data on your iOS devices after the last update. The following Knowledge Base article offers up some great steps for troubleshooting:

If you can‘t connect to a cellular network or cellular data

If you see No Service or Searching

If you see No Service or Searching on your device, or can't connect to a cellular network or cellular data, follow these steps:

1. Check your coverage area to make sure that you're in an area with cellular network coverage.
   • If you can't connect to a cellular network on your iPhone, make sure that cellular data is on in Settings > Cellular^*. On your iPad, go to Settings > Cellular Data.
   • If you're traveling internationally, make sure that your device is set up for data roaming. Go to Settings > Cellular > Data Roaming.
     
2. Restart your iPhone or iPad.
3. Check for a Carrier Settings Update.
4. Take out the SIM card and put it back in. If the SIM card is damaged, or doesn't fit in the SIM tray, contact your carrier.
5. Reset your Network Settings. Tap Settings > General > Reset > Reset Network Settings. This also resets Wi-Fi networks and passwords, cellular settings, and VPN and APN settings that you've used before.
6. If you have another device, see if you can connect your carrier's network with it in that location.
7. 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.
8. Update your iPhone or iPad to the latest version of iOS.

If you still can't connect to a cellular network, and have confirmed with your carrier that there isn't an issue with your account or network, try restoring your device.

If you can connect to 3G but not 4G LTE

Make sure that your device is compatible with LTE. Go to Settings > Cellular > Enable LTE. Identify your iPhone and compare its model number with the list of supported LTE carriers for your country or location. Or identify your iPad and compare its model number with the list of supported LTE carriers for your country location. LTE options might vary depending on your carrier's network.

In some countries, you might see Mobile instead of Cellular. For example, you might see Settings > Mobile or Settings > Mobile > Mobile Data Network instead of Settings > Cellular or Settings > Cellular > Cellular Data Network.

Additionally, if you're concerned about losing content, make sure you review the information here on options for backup:

How to back up your devices using iCloud or iTunes

Thanks for reaching out to Apple Support Communities.

Kind Regards.