Terriculum

I have created a system of video surveillance in my city. We are using around 60 cameras that are connected with optic fiber to one point where EVS storage and Dahua 7016 server are. Everything worked fine on tests but in last few days something weird happening. Some cameras are lost connection to EVS storage. That can be seen on picture "1". Picture 1 I have tried to upgrade firmware, restart it, delete it than to add it again and nothing. I have done factory reset too and that didint help. What is most confusing is that no other NVR cant see them atm. On picture "2" can be seen that camera that cant be seen on EVS is actually normally working... Picture 2 Cameras are different types, so its not a problem with one model only. This is not a regularly problem that can be solved with something like restarting so I need someone who had same problem before. This is log file from EVS at the moment when some cameras stooped working: