1
Verify the likely cause
Disable high dynamic range, select a fixed 60 Hz mode and update the monitor firmware before testing another certified cable.
FULL AI ANALYSIS
External monitor flickers over USB-C after macOS update
Generated Sep 6, 2026, 11:54:26 AM
Analysis summary
The reported behaviour is consistent with the update renegotiated an unstable high-bandwidth color mode over the USB-C link. The safest next step is to verify that hypothesis with a reversible test before making permanent configuration changes.
Possible causes
The update renegotiated an unstable high-bandwidth color mode over the USB-C link.
79%A recent software, firmware or configuration change is exposing an existing compatibility issue.
35%Suggested fixes
2
Validate and monitor
Reproduce the issue once after the change, review relevant logs or metrics, and keep a rollback path until the system has remained stable.