The strange this is, when you reboot your phone into Safe Mode, which is something that Nokia Support asked me to do, the camera works fine. But when you actually use your phone in normal usage, the camera performance is abysmal in terms of lags and crashes. My phone hanged and reset twice just becuase of using the Instagram camera
I suspect that this might be due to the 4G/LTE problem:
I have experienced the camera problem but not since turning off 4G. My phone has been rock solid since doing so, including taking a fair few photos.
I suspect the camera app is getting the location when it starts up and getting the location can (by default it does) use phone signal to help get an accurate position which probably triggers the 4G bug if you are using 4G.
hmmm possibly? in that case, should the phone not hang when in airplane mode?
Try going to the app permission settings and disabling location services (you'll lose geo-tagging). I heard there's a bug with it. I'm trying it out now, seems like it's better, but I'll test more tonight.