The monitor of the BM01, BM03, and BM04 models does not support simultaneous volume adjustment for audio from two cameras in split-screen mode.
When in split-screen mode, volume adjustment is limited to the audio from the currently selected camera view.
If you want to adjust the volume of both camera views, please first select the desired camera's view on the monitor, and then adjust the volume one by one.
If you still need help, please send us an email at support@momcozy.com.