Screen Flicker Immediately After macOS 15.1 Update

I have (temporarily) resolved the issue by:

• Creating an APFS Volume (e.g., sequoia_v15) with 25GB reserved space and no quota limit
  • See Add, delete, or erase APFS volumes in Disk Utility on Mac
• Downloading the Sequoia 15.0.1 installer (earliest version for me that did not have the issue for external monitor [plus Anker 778 dock]) using command:

softwareupdate --fetch-full-installer --full-installer-version 15.0

• Installing the Sequoia OS to the newly created volume (e.g., sequoia_v15)
  • Once the above command completes, go to Applications, and click on Install Sequoia, and select the new Volume created
  • After the installation, the Startup Disk was automatically set to the new Volume, so I didn't have to manually set the Startup Disk
• Disable the Software Updates until the issue is resolved by Apple, or a workaround is found

Just to summarize, this issue is not specific to Anker dock IMO - since I use the same dock and external monitor (Dell U3415W) with other laptops without any flickering or blanking issues.

Hope this helps.

Apple - please take a look at this since this is preventing from getting security updates.

Thanks.

After updating this broke:

1. M1Max 14" MBP
2. M4 Mac Mini
3. uni USB C to HDMI 2.1 Cable
4. LG OLED 32GS95UE-B.AUS

Zero issues and absolutely loved this setup on my M1Max running both Monterey 12.7.6 and Sonoma 14.7.1. 4KHDR@60Hz output was flawless no matter the Thunderbolt port.

Sequoia 15.0 and 15.1 update broke this. I was able to confirm this is not a hardware issue with the brand new Mac Mini running 15.1. Both MBP and MM fully detect the monitor but no resolution, refresh rate, color space or orientation change enable a clean picture out of either machine. The picture occasionally flickers in then immediately fails.

It appears any device running Sequoia 15.x no longer works with this cable. To mitigate this issue I am using a full bandwidh HDMI 2.1 cable and that is working as expected with macOS 15.1 and both the M1Max MBP and M4 Mini.

[Edited by Moderator]

This is not an Anker-derived problem (though they may have a fix for their dock).

As other posters shared it is persistent in multiple docks and even sometimes direct connecting to monitor. It stems with some change that happened in Apple’s 15.1 update, likely with how they are sending data downstream through TB4.

I posted a solution that works for my Anker dock going through its TB4 port using a Cable Matters TB4-HDMI adapter. I actually had to update the firmware on the adapter itself (insane) for it to work but it does work perfectly and restored my connection to pre- 15.1 performance.

From everything I can tell the update made the connection from the Mac —> Monitor extremely cable- and/or dock-dependent as another poster shared they had success with a different brand’s dock.

This is on Apple to fix and 3rd party connection suppliers are addressing (or not) on their own.

I really wish we’d get an official response from 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.

@Popal24 @diogocnunes The reply from Anker support indicates that they know it is an issue on their end.

It's awesome if Apple does fix this through a macOS update, but based on what we know today, I wouldn't expect them to address this - since it's an Anker Issue.

I will continue to share any updates I receive from Anker Support, and if any of you contact/hear from them I hope you'll please share your updates here too. They offered no timeline, so we should continue using macOS 14 or as Popal did, switch docks.

I've got an M4 Pro Mac Mini with 15.2 with three monitors: one via Thunderbolt directly, one via HDMI, and a second via the HDMI port on an Anker 778. The two HDMI ports are actually connected to a 4x2 HDMI switch so I can move all the monitors over to my PC via Dell Display Manager for the main display and the switcher for the two HDMI monitors.

I tried several monitors and several HDMI cables, but on the monitor routed to the Anker 778 HDMI port I was alway getting horizontal white or green lines flashing on the screen every so often, or 2-3 times per day it would just blank out for a second or two. I never had any trouble with the Mac Mini's HDMI port. After trying to rule out the cables and monitors as the cause, I replaced the Anker 778 with no change.... and that same day I found this thread.

This morning I applied the 15.3 update and haven't seen any flickering or dropouts since.

Using a M3 Max MacBook, just updated and the same issue with the Anker 778 connected via HDMI. I've tested HDMI and DisplayPort through the dock and have the same horizontal line flickers/signal loss. Connected directly to my Mac via USB-C or HDMI everything works fine. Dock is updated to 1.2.7, Seqouia 15.1. Hope a fix is out soon, I like just plugging one cable in for charging and a second monitor.

The HDR setting will be in system settings > displays (Then click the display that is flickering) > Then turn off High Dynamic Range (HDR)

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.

I ordered a TB to Displayport adapter from OWC and plugged it into the the TB port on the Anker dock, and then hooked that adapter up to my external monitor. There were NO issues. The dock is passing the video stream correctly to the OWC adapter which displayed video as expected. The issue lies somewhere within the Anker dock and how they are processing video from the TB stream

https://eshop.macsales.com/item/OWC/TB3ADP2DPT/?utm_source=google&utm_medium=shoppingengine&utm_campaign=googlebase&wickedsource=google&wickedid=EAIaIQobChMIzKGfk8-0igMVwFVHAR1A-zaYEAQYASABEgJynvD_BwE&wickedid=&wcid=17542428849&wv=4&utm_term=&utm_campaign=&utm_source=google&utm_medium=cpc&hsa_acc=9360794409&hsa_cam=17542428849&hsa_grp=&hsa_ad=&hsa_src=x&hsa_tgt=&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&gad_source=1&gbraid=0AAAAAD_cuHSxXAIB1FFVvuJbDVQIfkeLE&gclid=EAIaIQobChMIzKGfk8-0igMVwFVHAR1A-zaYEAQYASABEgJynvD_BwE

Hi I am having the same issue, Anker 778 with a 4k@120hz monitor connected through it is flickering, if I change it to 60hz it works fine, issue only comes when I set it to 120hz or higher. My third monitor which is connected directly to my M1 pro is not having issues and it is also running at 4k@120hz, I am thinking this is more of an ANKER 778 Dock Firmware issue or Apple changed something that the dock is not expecting and is not working nicely.

very annoying, allot of people seem to be having this issue based on other platforms ive seen such as Reddit.

UPDATE (potential solution)

On my Anker 778 dock I added a Cable Matters USB-C to DP 2.1 adapter with a DP 2.1 cable to the downstream Thunderbolt port and no longer have issues. Running 3400x1440 UW at 144HZ no drops or lines. The DP cable even goes through a Cable Matters KVM switch too before hitting the monitor (unchanged from prior setup).

If anybody else has this adapter or picks it up, please share your experience.

Cable Matters 80Gbps USB C to... https://www.amazon.com/dp/B0CLZ9TZ5Q?ref=ppx_pop_mob_ap_share

I had already updated to the latest public beta of Sequoia so cannot confirm

Update: Wiping the laptop and reverting to macOS 14 fixed all dock video issues. I will hold off on Sequoia until this gets addressed.

I confirm that Sequoia 15.3 fixed the problem with my Anker 778.

No more flickering nor signal loss. Everything seems smooth and stable.

I also could confirm Sequoia 15.3 fixed the problem with my Anker 778!

Hope it stays this way.

Thanks all for your help.