Why does a terminal command launch another BetterDisplay instance?

When calling the app executable, include an operation such as help, get, set or perform. Write the operation without leading hyphens. If the arguments contain no recognized operation, BetterDisplay can start another app instance.

For help, use:

/Applications/BetterDisplay.app/Contents/MacOS/BetterDisplay help

To request reconnection of displays, the operation is perform and the action is a parameter:

/Applications/BetterDisplay.app/Contents/MacOS/BetterDisplay perform -connectAllDisplays

An action name by itself is not a complete command. Likewise, --help is not a substitute for the help operation when calling the app executable. Reconnecting a display requires Pro, a supported connection and settings that allow the operation.

You can also use the betterdisplaycli helper, with the same operation-and-parameter structure:

betterdisplaycli help
betterdisplaycli perform -connectAllDisplays

See CLI examples for complete requests and the command reference for available operations. If each attempt adds another menu-bar instance, correct the command before running it again.