Iphone 7+ is having a problem again

My Iphone 7+ all of sudden not working properly on any kind of call/video call. I have tried all solutions which I found on official Apple website including restoring to the manufacture setting but still having the same problem. All now the camera can't even take any pictures or videos, it is really frustrating these issues all of sudden happens. Any real solutions or explanation from Apple why these problems are happening now. Or anyone else have or had the same issues? Any helps will be much appreciated.