Week old iPhone 7 shows "invalid sim" error
Week old iPhone 7 128 gb shows "invalid sim" error intermittently. Nothing in particular seems to cause it. Just shows up randomly. If I power down and reboot it resolves for a while. I'm getting once or twice a day now. Anyone else having this issue? How do I fix it? I plan to go back to the Apple Store where I got it tomorrow.
iPhone 7, iOS 10