my phone keeps going black in seconds help

What do you mean?

Your device autolocks itself very quickly? Check Settings>Display&Brightness> AutoLock .. adjust the time.

Your screen goes black and the iphone is frozen?

If your iPhone, iPad, or iPod touch won't turn on or is frozen - Apple Support

Regards

Giulio

Did you find a fix for this? My phone does this also

My auto lock is set for 2 minutes but my screen goes dark after just a few seconds. I can lift my phone and my display pops up again but then almost immediately goes dark again. I would prefer my screen remain visible until my auto lock kicks in. Is that possible?

Mine is doing this too. Whenever I touch the top of the phone it goes black for a couple seconds then comes back on