CCTV system problem


I have Hikvision CCTV system(cameras and network video recorder)

4 cameras (model- DS-2CD2043G0-I 4mp), 36 cameras (model- DS-2CD212WF-I 2mp) and one DS-9664NI-I8-8TB 64 CHANNEL network video recorder

I have installed all the hardware. I used the Cisco Catalyst 2960-X Series (POE) switches and connected all cameras to cisco.

I configured video recorder, installed new 4 HDDs and turned on the CCTV system

I thought the CCTV system was working well, but I noticed that the recorded video had some drops.

I reduced the camera quality, but the problem doesn’t fix

the camera bitrate is 4096kbs for 4mp cameras and for 2mp is 2048kbs.

I have changed the video recorder and changed it to a new one, also, I have changed some cameras, but the problem didn’t fix.

I need to recorded video wouldn’t have dropped, I don’t want to miss any moment in recorded video.

If you have any experience in this sphere please advise me on how to fix this problem