Screen Flicker Immediately After macOS 15.1 Update

Having the exact same issue on my Macbook Pro M3 Pro... immediately after the update I was getting black screen flickers and screen tearing on my Alienware AW3423DW 34" 3440x1440 HDR 165hz monitor. I tried restarting (again), reseating cable, lowering refresh rate and resolution, display mirroring, etc. Still flickers between lost signal black screen or screen tears (even on static image). Using an Anker 778 Thunderbolt 4 Dock (fabulous solution for Macbook and a Win desktop) with latest firmware.

Will try turning off HDR when back at my screen but it is certainly isolated to the 15.1 update. Only change made before issue. ** Ryan (@whippetranch)

This! I have flickering horizontal white lines immediately after updating to MacOS 15.1. M3 Pro MacBook Pro with external display connected via HDMI to Anker 778 Dock.

Re-seating / swapping HDMI cable has no effect.

Toggling HDMI also no effect.

DP TX wrote:

My monitor started an odd flicker and ghosting of images almost immediately (less than 5 minutes) after performing macOS 15.1 update. Monitor is connected via HDMI and has not had this problem with any monitor in the past.

Also using a Mac Mini M2 updated to Sequoia 15.1

The External Display is Directly Connected via a HDMI cable from Display to female HDMI connector of the computer

Sometimes when connecting a USB-C Drive to the computer

I have inadvertently touched or nudged the HDMI Cable for the Display

You may consider Reseating the Display Cable on the computer

An aside to to your actual issue

The Apple Support Community Forums are sometimes visited by AI / LMM / ChatBots.

AI / LLM are basically a Super Version of Predictive Text which is based upon a Data Set.

When that Data Set is based upon older data points, the outcome of the response will be equally out dated and / or  unreliable

Suggest being very careful about this.

Some suggestions can be incorrect, misinformed , incomplete, impossible to do, out right wrong.

If your machine is an Apple Silicon M1,M2,M3 computer

Resetting the SMC and Or NVRAM does not apply at all

I have exactly the same problem since the update to 15.1. The monitor keeps losing the signal, turning off and on again, but at different intervals. It's a pain.

My system is a: MacBook Pro M1 Pro with an external LG 32-inch monitor

I wonder if this has something to do with the Anker Dock - I am also using the 778 and having similar connection issues with one of my displays immediately after upgrading to Mac OS 15.1 on my M1 MacBook Pro . I tried connecting my DisplayPort monitor to the other port on the Anker dock and seem to be getting better response.

Having the same issue on my Apple M1 Max MacBook Pro after 15.1 update. I'm plugged into an Apple XDR Monitor with Apple ThunderBolt 4 cable. Super frustrating cannot use it, laptop plugs in, hear battery is charging sound, monitor flickers on, then goes to black, I hear power unplugged sound, repeat.

What's the fix, Apple?

I have the same issue with the same Anker 778 dock. This has worked for the last year without issues. In that time I've used a M1 MBP and a M3 MBA without issues. Immediately after updating to macOS 15.1, I started experiencing minor horizontal line flickering and signal loss black screens every 30-90 seconds. It's work-stopping and literally makes this Samsung G9 unusable.

In case anyone wanted to try any other docks, I ordered a replacement Anker 778, Anker 575, CalDigit TB4, all new cables, many active DP to HDMI adapters with no change in behavior. The one thing that did work, was to use the CalDigit TB4 dock (which only has DP output) and directly use the DP input on my monitor which seemed to be working ok. My display only has 1 DP (and 2 HDMI) inputs and I need the DP input for my gaming PC so swapping to DP is not an option for me.

I had a troubleshooting session with an Apple senior advisor and we checked everything and they offered no solution. They blame the dock/monitor and suggested I use an Apple display. They also said this issue was not on their issue tracker so please keep posting and upvoting here.

My old M1 works fine via the old Anker 778 through HDMI (it's on macOS 14.6.1). I updated the display's and dock's firmware without success.

There seems to be some change to how macOS deals with downstream displays in the new macOS update. I suspect there is some bandwidth issue thats affecting the output on HDMI via a dock/hub. Using an Apple branded USB-C to HDMI adapter works without issue so it's something downstream through the dock.

I'm having the same issue. Started as soon as the update was complete. Doesn't matter what setting I change on my M3 MBP. The external monitor won't stop flashing horizontal flickers across the screen every second.

Update: I was able to get the flickering and screen shuttering to go away by disabling HDR in the display settings. But this is an HDR monitor and it was working before the update. So at least I can get some work done, but the image is awful. It looks so washed out.

How were you able to turn off HDR? On the display itself, or somewhere in display settings? I still see my displays listed there, and have the same exact issues (when first plugged in, a quick flicker, then go black, but are still detected).

I don't see any options for turning off HDR in the settings.

Same issue, flickering screen since the upgrade to 15.1 on a M1 Mac Studio using a USB-C to display port cable.

It is a little nuts for them to recommend new hardware for something they broke in software.

For the sake of testing, I updated my M1 on 14.6.1 to 15.1 and it started with the same behavior. So it must be update related.

I'm having the same issue after updating to macOS 15.1. In my case, though, the horizontal white lines appear on 85% of my MBP 16" 2023 M2 Pro screen from left to right. I'm wondering if anyone else has had that issue (not on an external display but on the MacBook's display itself).

I am having flashbacks of my last MBP (2018 15") which eventually lost all display functions starting with little lines (in that case, vertical). But that seemed to be a hardware issue eventually suffered by many other people using the same model from that period.