I just had about 4 hours of hell with a similar issue. The advice on this thread and website saved me. thought I'd document what i did in case some other poor soul gets stuck on the same hurdle.
Cameras (IPC-HDW4631C-A, 6MP POE IP67)
NVR (4K NVR4104-P-4KS2 ACH 4POE)
IP Address of NVR: 192.168.1.108 (Default)
IP Addresses of cameras: 192.168.1.108 (Default)
Subnet IP of cameras set by NVR: 10.1.1.65-68
NVR Username: admin
NVR Password: *********** (whatever you set it as)
Camera default Username: admin
Camera default Password: admin
Each camera has a default IP of 192.168.1.108 out of the box
Caution The NVR assigns each camera an IP of 10.1.1.X once you plug them in. If the password you've set on the NVR is different from the camera default username and password (admin:admin), the camera gets stuck and will display: ‘incorrect username or password’ or ‘account locked’
You need to log into each camera separately first, using separate 12V POE.
(Router LAN Port > POE Injector or Switch > Camera)
(If it’s too late, and the NVR has changed their IP’s already, then you need to unscrew and open each bullet cam, hold in the K1 jumper while powering it on, keep held for 60sec. This resets it to default. There's videos on youtube that show you where the jumper is located)
Log into camera directly via a web browser using 192.168.1.108 in the address bar.
You will not be able to see the device if the computer you’re using is not on the same network gateway. if necessary, change the computer’s static IP to 192.168.1.X, and default gateway to 192.168.1.1, then ping the camera from terminal or cmd using 'ping 192.168.1.108' to check you can reach it.
Once logged in (username admin, password admin), go to settings and change the password to the same password you set on the NVR, change the IP to 10.1.1.X and gateway to 10.1.1.1. hit OK or apply.
The webpage will stop responding because the computer is now again on a different gateway.
Now you can disconnect the camera from the POE, plug the camera into the NVR. The NVR will do its thing and the image should pop up on screen.
Remember to change your computer's IP settings back if necessary.