Screen Flicker Immediately After macOS 15.1 Update

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 don't think it's Anker specific. I've tried a different Anker dock model, a replacement 778 and a CalDigit TB4 dock and they all had the same issue.

I experience the same issue with the following :

• MBP 14 M2MAX
• Anker 778 dock

1st monitor is a 4K60 32' BenQ connected from the dock over USB-C => no issues

2nd monitor is a 1440p75 27' Dell 2771S connected from the dock over HDMI or DP => flickering in both cases

No issues with the same setup with a Windows computer (Intel 10th gen over TB).

Anybody tried the latest 15.2 Developer update?

The original installation remains untouched, and all the documents/files are still there, however, I had to re-install the Applications for the new install.

For example, the original volume was (in my case) "/Volumes/Macintosh HD", and the files were accessible as usual:

$> ls -l /Volumes/Macintosh\ HD/Users/<user_name>

and the files for the new installation are under:

$> ls -l /Volumes/sequoia_v15/Users/<user_name>

Not sure if the Applications from the original installation location would still be able to execute, and most likely they won't be able to execute from the original installation, since the OS version and Library locations etc. are changing.

Creating a new Volume, installing the latest OS version with softwareupdate command gives chance to try the latest OS version(s) to see if the issue is resolved 8-)

Hope it helps.

Thanks.

Same problem here. I have an older M1 macbook pro, no issues until I installed Sequoia (and this wasn't the only issue. My laptop no longer updates properly, always entering safe mode after an update, and there were numerous other things that just went nuts after the initial update). It started flickering immediately after that, on my external monitor.

I also have a newer M2 Studio that I bought late last year, attached to a new 39" Ultrasharp at the same time. No issues at all, installed Sequoia, and now every few minutes it flickers. This is 100% an Apple software bug, which they refuse to acknowledge. I was planning to upgrade my M2 studio and possibly my M1, but no chance in you know where after the horrible experience I've had with Sequoia. Apple is officially the new Microsoft!!

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.

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.

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

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'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.

I have the same issue with an LG Ultra Wide monitor connected through USB-C suddenly the screen blinks for a second and shows the picture again. It's very annoying while I'm working.

I'm also on 15.1.

I just updated to macOS Sequoia 15.2 (24C98) on my MacBook Pro M1, and unfortunately, the issue with the external monitor connection is still unresolved. I’ve been dealing with this for quite a while now, and honestly, I’m losing patience. I really hope Apple can provide a more effective response soon.... It's so annoying...

That sounds like a different issue than this thread is experiencing, most/all the posters have been talking about the Anker 778 dock. Maybe I've missed something though: I will re-read the discussion.

Edit to add: It feels as though two different threads (One for Anker 778, one not) would be beneficial to keeping these issues straight... As the OP's question was specific to the 778 dock as are about 2/3 (roughly) of the replies, a fresh thread for not-docked may be ideal.

Alright, I will defer to you WhippetRanch.

I still think they're separate issues and that it's Anker's fault based on Anker's reply, but frankly it sounds like either of them *could* do something to address the problem for their end regardless of who "owns" it.

(My testing was done with an official Apple Thunderbolt Video Adapter plugged into the Anker 778's TB Out port and it did nothing to remedy the situation - To be honest with you if the OEM Apple adapter doesn't work in that scenario then the absolute last thing in the world I'm about to do is start throwing more adapters at it.)

Updating this thread. It appears macOS Sequoia 15.3 does not resolve this issue at least for me. Display continues to remain unavailable and it appears to flicker as the laptop and display attempt to negotiate a connection.

Pretty disappointed. Using a full size HDMI 2.1 cable continues to be the only way for me to connect to the monitor.