Fix Guide: Stage Manager Flicker on macOS Sequoia

Symptom: When switching between app groups in Stage Manager, the screen flickers, or the "strips" on the left side disappear and reappear randomly.

Why this happens

This is typically caused by a mismatch in the refresh rate on ProMotion (120Hz) displays or a conflict with the "Automatically hide and show the Dock" setting in macOS Sequoia.

Recommended Troubleshooting Tool

Before proceeding with manual fixes, we recommend using CleanMyMac X. Quickly identify high CPU apps and optimize system memory with one click.

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Fix 1: Adjust Dock Settings

1. Go to System Settings > Desktop & Dock.
2. If "Automatically hide and show the Dock" is ON, try turning it OFF.
3. Stage Manager relies on the Dock's visibility state to calculate the "strip" width; having both dynamic can cause the flickering.

Fix 2: Force Quit WindowServer

If the UI feels "stuck" or flickery:

1. Open Activity Monitor.
2. Search for WindowServer.
3. Click the X to quit it (this will log you out immediately).
4. Log back in. This restarts the entire Sequoia compositing engine.

Recommended Tool: CleanMyMac

GPU-related UI glitches are often tied to full system caches.

- Run CleanMyMac's Maintenance scripts to "Flush DNS Cache" and "Speed Up Mail," which also triggers a refresh of the system UI cache, often resolving Stage Manager artifacts.