MacBook Pro ultrawide monitor randomly fades to black after macOS update

Hi everyone! Looking for insight or to see if anyone else is encountering this issue after updating macOS today.

My Setup:

Mac: MacBook Pro (M5 Pro)
OS: Latest macOS 27 update installed today
Monitor 1: 1680x1050 connected via USB-C (works completely fine, no glitches)
Monitor 2: 3440x1440 Ultrawide connected via USB-C (affected display)
MacBook Built-in Display: Functioning normally both opened and closed

The Issue:

Ever since applying the update, the 3440x1440 ultrawide monitor randomly fades to black. The backlight stays powered on, but there is no image/signal rendered.

The other external display (1680x1050) and the built-in MacBook screen continue working without interruption when this happens.
Power cycling the ultrawide monitor or unplugging and reconnecting its USB-C cable immediately restores the picture until the next random fade-out.
Prior to today’s update, this exact setup ran without any issues.

Has anyone seen similar display pipeline issues on ultrawide resolutions with the recent update? Any workarounds (DSC, refresh rate, or color profile tweaks) would be appreciated.

Posted on Sep 17, 2026 7:56 PM

1 reply

jepedregosa Author

Level 1 (4 points)

Sep 17, 2026 10:27 PM in response to jepedregosa

Edit: I think it has something to do with the refresh rate. I lowered down the refresh rate to 60hz and the issue so far is fixed. But I hope this gets fixed permanently because 144hz worked perfectly before the update.