iPhone 7 plus unexpected shutdown in every 2 min.

Hi

Have you got the latest ios software 11.2.1 go to settings -general -about -software update over your wifi.

Cheers

Brian 🇬-1F1E7;

This is happened with me in iPhone 8 too :(

Update to the latest iOS11.2.1

Your issue will be solved.

Actually it is not really rebooting.

Only springboard is crashing/restarting.

I m also facing same issue in iphone 7 plus even after updated to ios 11.2.1

Also I restored it as new