Do they have audio when exported and played in another viewer? And are u playing it at the normal 1x speed because other playback speeds dont play audio.
I saw someone made a new blue iris integration for Home assistant GitHub - kramttocs/ha-blueiris: Home Assistant Integration with Blue Iris Video Security Software . If anyone wants to try it and tell us how it is. READ the github instructions before anything.
maybe your cameras are to old. DId you change the ptz driver in the camera ptz/control settings to dahua v4, which i think is required to do. And maybe a new find/inspect click under video>configure.
Ptz cameras from Dahua support it, it’s in blue iris and ui3. It lets u draw a box on any part of the screen and depending on the color and size, it will zoom into it or out of it quickly