Skip to content
MappleCare Community ↗

MappleCare Community

[Solved] MacBook Pro 14″ M1 Max encountering External Display Flickering at High Refresh Rates after update (macOS Sequoia 15.1)

Find answers from other Apple users or start a discussion about your device.

All Forum Rooms

Home › Forums › MacBook, iMac & macOS Lab › [Solved] MacBook Pro 14″ M1 Max encountering External Display Flickering at High Refresh Rates after update (macOS Sequoia 15.1)

Viewing 2 posts - 1 through 2 (of 2 total)
  • Author
    Posts
  • November 15, 2026 at 5:02 am #20037
    Penelope Young
    Certified Tech (Lvl 5)
    Diagnostic Hardware Specs: MacBook Pro 14″ M1 Max | OS Version: macOS Sequoia 15.1 | Archive Source: Apple Support Community #256469924

    I am running into a persistent issue on my MacBook Pro 14″ M1 Max running macOS Sequoia 15.1.
    Whenever the machine encounters DSC compression and VRR handshake failure over USB-C DisplayPort, the following diagnostic log appears in Console:

    WindowServer: [com.apple.WindowServer:server] Display 0x4ea5 link training failure / DSC buffer renegotiation

    I verified that hardware connections are intact and tested across different power sources. What is the verified diagnostic procedure to permanently eliminate this symptom?

    MacBook Pro 14″ M2 Max (32GB) | Pro Display XDR | iPad Pro 13″ M4 | Seattle, WA
    Product Designer & Design Systems Lead | "Verified Apple Discussions Archive"
    November 15, 2026 at 5:02 am #20038
    Elijah Burns
    Community Contributor
    Apple Recommended / Verified Community Solution
    This canonical solution was verified and marked as solved in the Apple Support Community archive.

    Locking refresh rate to a fixed frequency, disabling Variable Refresh Rate (VRR), and regenerating WindowServer display plists.

    Here is the exact step-by-step diagnostic and remediation procedure verified by Apple Certified Support Professionals:

    1. In System Settings > Displays, set Refresh Rate to fixed 120Hz or 100Hz instead of Variable (VRR).
    2. Reset display preferences: 
      sudo rm -f /Library/Preferences/com.apple.windowserver.displays.plist
rm -f ~/Library/Preferences/ByHost/com.apple.windowserver.displays.*.plist
killall -9 WindowServer
    3. In monitor physical OSD menu, set DisplayPort mode to ‘DP 1.4 Standard’ without aggressive DSC overdrive.

    Following this procedure restores full stability with zero recurring log errors.

    MacBook Pro 14″ M4 (24GB) | iPad Air M2 | Keychron Q1 Pro | Dublin, IE
    Apple Certified Support Professional (ACSP) | Computer Science & Machine Learning Student
  • Author
    Posts
Viewing 2 posts - 1 through 2 (of 2 total)
  • You must be logged in to reply to this topic.