I have the HikVision DVR cameras outside my house and I usually use the app which works fine. Yesterday I got a new router so the app stopped working - keeps saying the device is offline. I tried to change the IP address on the set up network tab on the screen but it still isn’t working. The builders who installed it are being extremely useless so if anyone could help with this, it would be much appreciated. I am using model number DS-7204HQHI