New device wont unlock when slide

Hi! I got a new Iphone 13 for my sister.

We selected language, code/face ID and selected the option to migrate from her old Iphone. iOS 18.2 started downloading and the phone was restarted.

Now when we turn it on the welcome message appears as a new device and asks for a slide up but when I do it I get the code screen and it immediately goes back to the welcome message again. Its stuck.

It also doesnt allow me to turn it off for the same reason. 0,2 seconds if “insert your code” and it goes back.

Note: the iphone is warmer than usual.