The Shifting Icons
The macOS Dock is meant to be a reliable launchpad where you build muscle memory for the exact location of your favorite applications. However, macOS includes a feature that automatically shuffles the order of the icons on the far right side of the Dock (or the bottom, if your Dock is oriented vertically). It pushes the applications you have used most recently to the front of this specific section. While Apple intended this to make finding active apps easier, it constantly breaks your muscle memory and makes the Dock look messy and unpredictable.
How to Disable the “Recent Applications” Feature
To lock the Dock so that it only ever displays the icons you intentionally placed there, in the exact order you arranged them, you must disable the dynamic “Recent Apps” section entirely.
1. Click the Apple logo () in the top-left corner of your screen.
2. Select System Settings (or System Preferences on older versions of macOS).
3. In the left-hand sidebar, click on Desktop & Dock.
4. Look at the very top section labelled “Dock.”
5. Locate the toggle switch labelled Show suggested and recent applications in Dock.
6. Click the toggle switch to turn it Off.
The moment you disable this setting, the small dividing line on the right side of your Dock will vanish, along with all the temporary icons that were shuffling around. From now on, the only applications in your Dock will be the ones you manually drag and drop onto it, permanently stopping the automatic reorganization.