No mic audio annke cameras

[dba7108]

I have 5x annke nc800 cameras. On the main view of the app where it shows all 5 cameras i can hear the audio of camera no.1. If I go into any other cameras including no.1 there is no mic audio including on playback. I think these are basically hikvision cameras. Is this an issue with the nvr or the camera settings? Any advice appreciated!