Why is Input Source missing even though my monitor’s brightness control works?

Input selection is a separate DDC feature. A monitor can accept brightness commands without advertising or accepting input-select commands. First check whether BetterDisplay’s Input Source control is enabled, then verify that the monitor actually responds.

1. Open Settings > Displays > [monitor] > Device Control > DDC Control > Configure Controls….
2. Find Input Source and enable it if the monitor supports DDC input selection but automatic detection did not enable it.
3. Close that sheet, then choose Input Sources… in the DDC Control section and check the input list. Enable Customize input source list for this display if you need to adjust supported values, labels or menu visibility.
4. Open App Menu > [monitor] > Input Source and test a known supported input command. Keep the monitor’s own input-selection buttons accessible so you can switch back.

Enabling the feature only lets BetterDisplay send the command. It does not add firmware support to the monitor. The standard DDC input-select command is VCP 0x60, but accepted values and availability vary by model. Working brightness or contrast is not proof that this command works.

The default input labels are examples, not a detected connector map. Do not assume a value labeled DisplayPort selects the same physical port on every monitor. See input-source labels for editing the list and switching back after changing input for monitors that stop accepting commands from the inactive input.

If the menu appears but switching still does nothing, record the actual monitor model, connection, input value and capability/readback results. A missing menu and an ignored command need different explanations. A model-specific failure does not establish that input switching is absent from BetterDisplay.