iPhone clock app and other problems

When I try to set an alarm or do anything else with the clock app, the app shows blank screen.

I tried to set an alarm with Siri, and he said that there is a problem and he cannot do set the alarm.

Moreover, when I am using any other application, after a few seconds the phone shows blank screen and then sends me to the home screen.

I upgraded to 11.1.2 recently, but the problems started today.

I restarted the phone two times, but nothing changed.