With separate Spaces per display, macOS shows the Dock on whichever screen your pointer pushes against at the bottom edge. Casement can lock the Dock to a chosen display. Without it, the options are to move the pointer away from the bottom edge of the second screen or to turn off separate Spaces, which changes how full-screen apps behave.
Why it moves
The Dock appears on one screen at a time. If you drag the pointer to the bottom of another display and hold it there, the Dock jumps over.
Built-in options
- Stop at the bottom edge of the second display: stay a little above it.
- In System Settings, Desktop & Dock, turn off Displays have separate Spaces. That stops the move but changes how full-screen apps and menu bars work, and needs a logout.
With Casement
Choose the display the Dock should stay on, and it stays there whatever the pointer does. See the Dock screen feature.
Check your setup
- Open System Settings, Desktop & Dock and note whether Displays have separate Spaces is on. The jumping only happens when it is on.
- The Dock moves when the pointer is pushed against the bottom edge. A little room above the edge avoids it.
- If the Dock is set to hide, it appears on whichever display your pointer touches.
With Casement
- Open Casement's control panel.
- Find the Dock screen option and choose a display.
- Check by pushing the pointer against the bottom of the other display. The Dock stays.
Questions people ask
Will the Dock hide on the other screens?
The Dock is shown on the chosen display only, as macOS normally does.
Try Casement
Casement is a menu-bar app for Mac that puts each Chrome profile in the Dock as its own icon and adds snap layouts, hover-to-focus, a window switcher, Dock window lists, a drop shelf and display controls..