Hello,
I am sorry for the issues you are having. Not knowing this specific brand, I do not know the specific solution to your problem. I would highly recommend trying to login through the web browser and try to lower the screen resolution of the NVR. It sounds to me that the resolution that the NVR is outputting is too high for this monitor. I know with our Sibell Series line of product if you hold the left mouse button for 5 seconds it cycles to the next lower resolution, and you can keep doing so until the monitor fires up to display. I wish I had more help with your specific product, but in my experience, if the mouse click does not work, login through the web browser to set the output directly there.