IOS 26.6 update connectivity issues

To fix apps not loading and internet connection failure after updating your iPhone 16 Pro to iOS 26.6, perform a force restart, disable or remove active VPN profiles, and reset your network settings via Settings > General > Transfer or Reset > Reset > Reset Network Settings. 

For the force restart this is how you do it

1. Press and quickly release the volume up button.
2. Press and quickly release the volume down button.
3. Press and hold the side button.
4. When the Apple logo appears, release the side button.

Is the problem using Wi-Fi, cellular or both? If it is only Wi-Fi restart your router.

And, while WheelieNick mentioned VPN, to be clear:

Do you have a 3rd party VPN installed, even if you are not using it? If so, delete the VPN profile in Settings/General/VPN & Device Management/VPN, then restart your device. Don't just turn it off; delete the profile. Updates sometimes "break" VPN, and it needs to be removed. If that fixes it, you can try reinstalling VPN, but probably shouldn't.

None of this has helped!