Cell phone always restarts?

My Huawei p20 lite always restarts. But not just once, but several times in a row. Sometimes it is so bad that it starts again while I enter the code. I don't know if it's really that, but whenever I briefly press the off button to turn the screen off, it also restarts. I urgently need help because my cell phone can hardly be used.

In a pinch, if there's no other option, you have to perform a hard reset.

Attention, then all personal data will be deleted and you will have to set up the mobile phone again.

Hope you have always backed up all data.

https://www.giga.de/...t%20die%20 "Volume up, selection% 20 with% 20 of the% 20 Power button.

I did it, but it didn't work, thank you anyway

Then a techn. There's a defect!