Leroy Tech

Hi all, I have a Hikvison CCTV setup as follows: 5 cabinets each with a 16 port Hikvision switch with gbic and fiber linking to one main 24 port Smart switch at the server room. roughly 14 cameras on each 16 port switch and the rest are plugged in directly at the 24Port. 2 x 64 channel NVR. I dropped the resolution, bitrate and frame rate on each camera, and both streams no change on the network issue. The issue I have is lagging on the network, cameras are stuttering on display directly plugged into NVR and using IVMS, it's a standalone system no DHCP or other devices connected only NVR and cameras. Need help or advice, without the NVRs plugged in I can ping all my cameras with 1ms ping, as soon as I connect either NVR onto the network it starts lagging up to 800ms pings. I'm using 5 x UFiber AE Converter at the central 24 port switch, I even tried using the sfp ports on the switch to see if it makes a difference still no change, I tripled checked for duplicate IP addresses as well, I tested with media converter at the 16 port and at the 24 port still no change. Tried to use Switches configured with static IP and inactive but no change on my situation. I'm throwing my hands in the air and can't seem to find the fault, both NVRs are on the latest firmware. Did anyone experience this issue before, currently it looks like the NVRs are the problem. help please