Why does my monitor stay silent after I raise the volume from zero?

The monitor may handle its mute command separately from its volume level. Raising the volume can therefore leave it muted if the monitor does not accept the unmute sequence BetterDisplay is using. Check the mute method instead of assuming that a moving volume indicator proves sound has been restored.

Open Settings > Displays > [display] > Device Control > Volume Control…. For a display using DDC with mute support, review Mute Method, Unmute Method and When Volume Reaches 0%…. These options are separate from choosing the audio output in macOS.

• If the monitor needs unmute before the volume write, try Issue unmute command first, then set volume level under Unmute Method.
• To avoid automatically sending a mute sequence at zero, choose Set volume to lowest setting under When Volume Reaches 0%….
• If the monitor’s explicit mute command is unreliable but its minimum volume is silent, Set audio volume to lowest setting only and Set audio volume level only let mute and unmute use volume writes instead.

Change one choice at a time and test both lowering volume to zero and pressing the mute key. Keep the monitor’s own mute button available while testing. A minimum-volume setting is not silence on every monitor, and no single method is a confirmed fix for every model. The monitor may also mute itself when it receives its minimum value.

If those groups are absent, check Feature Availability and the selected controller. Native audio association and command-only remotes use different paths. See Volume Control for the complete method choices and their scope.

For a step-by-step walkthrough, follow Fix mute and unmute on an external display.