How to fix an iPhone 8 that is connected to a Wi-Fi network but no Internet access

Corrupted Wi-Fi networks saved on your device can cause Wi-Fi problems. These saved networks may have been impacted by random defects from the recent software upgrade, which has an impact on their behavior. To eliminate them as a possible source of the no internet access issue, erase all saved Wi-Fi networks and reconnect to the chosen one using the instructions outlined below:

1. Navigate to Settings from the Home screen.
2. Choose WiFi.
3. Find the WiFi network you wish to forget, then hit the information I icon next to its name.
4. Select Forget This Network.
5. Read the warning popup, then press the Forget button to confirm.