"Select a Wireless Network" - It can not be closed

Hi,

1. I updated to iOS 11.2 on my 16GB iPhone 6 plus without any issues.
2. I opened the Chrome browser and the message "Select a Wireless Network" appears.
3. By clicking on CANCEL, the message cannot be closed.
4. The phone cannot be used, cannot be restarted.
5. Siri could not help.
6. I pressed and hold the side button until the slider appears. I cannot drag the slider to turn the device completely off.

Thanks