when i use the monitor, the camera closes immediately and sometimes stay open for a second a then closes again

Which Minecraft version and which SecurityCraft version are you using? When reporting issues, please always note down these things as it makes it easier to know where to start looking for the issue.

i am in 1.16.5 and security craft is in version 1.9.7.1

I can't reproduce this. What other mods do you have installed? Are you trying to use this in singleplayer or multiplayer?