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DenisOvidiu Author

Level 1

52 points

MacBook Pro M1 Pro issue with dual display after updating to macOS Sequoia 15.1

Hello,

Yesterday I updated my MacBook Pro M1 Pro to macOS Sequoia 15.1.

All the time I have my laptop connected to an external display. After the update, instantly I got a problem where randomly my external monitor is turning off (like when you are unplugging the external display cable or stopping the "extended screen" from settings) and the main screen (that is on my external display) is moving to the laptop and in just one second, the monitor is "turning on" and everything is back to normal.

This is happening like 1 time each 2 3 minutes which is really annoying.

What I tried so far and the issue persist:

Change with 3 other cables - Same issue
Using another monitor - Same issue
Restart laptop

MacBook Pro 14″, macOS 15.1

Posted on Oct 29, 2024 1:11 AM

Top-ranking reply

smk235

Level 1

20 points

Posted on Oct 30, 2024 9:00 AM

Having a similar issue on my MacBook M2 Max. I have 3 x external monitors, 1 x running on HDMI cable & 2 x running on USB-C to HDMI cables. The monitor running on the HDMI port has zero issues, the 2 running off the USB-C ports will turn on for a few seconds, I can see my desktops than both go black within a few seconds. I've tried everything and still have the same issues. Very frustrating.

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47 replies

Nov 15, 2024 8:06 AM in response to DenisOvidiu

Same problem here on an M1 MacBook Air. It's not all monitors though. It's just my 4K monitor that keeps disconnecting and reconnecting. My two 2.5K monitors seem to be fine.

Really frustrating as my 4K drawing tablet is now useless until this is fixed.

Nov 20, 2024 5:17 PM in response to DenisOvidiu

I was having this issue running 3 external 4K monitors through an "iVANKY FusionDock Max 1" dock and routed through an HDMI KVM. At first, I thought my issues were due to my Thunderbolt to HDMI cables or my KVM setup.

I tried multiple fixes, but ultimately, the problem was only solved after switching to the Apple 1M Thunderbolt 5 pro cables between my dock and my M3 MBP instead of the cables that came with the dock.

Apple definitely needs to develop a software fix, but for those dependent on external monitors, this might be an (expensive) workaround.

I tried other cables, even those marketed as Thunderbolt 4 and 100GB USB-C, and even reverted to MacOS 14.7 for a while; this was the only fix that worked for me while running MacOS 15.1.

til666

Level 1

14 points

Nov 21, 2024 10:08 AM in response to diogocnunes

First of all, you need an image. This can be downloaded from several websites - Sorry, I am on iPhone here and can’t post the links that you will find them if you really want to

Download the.PKG installer

Then install it and from your applications folder using terminal (there are scripts around, it’s not too hard but it takes a while, I almost aborted due to missing progress…), you can create a USB boot, medium

Be sure to have a time machine back up that was made on 15.0.1 otherwise it won’t work

Then reboot your Mac holding The startup key and boot Into options

Repartition Your hard drive. (completely delete)

After that reboot or select your USB boot medium and install Sequoia 15.0.1

Now you can use your Time Machine back up to restore your Mac. If you don’t have one, you have a Mac on factory settings now

So much for an ultra short info, that worked for me

HME1969

Level 1

0 points

Nov 22, 2024 9:24 AM in response to DenisOvidiu

Same issue here..... MacBook Pro M1, external screen Philips Widescreen....... Really I got a 2nd MacBook for work... but if I had that updated.. I really had a issue. Why does it take so long to fix.....

ZiaDaisy

Level 1

12 points

Nov 13, 2024 12:43 AM in response to ZiaDaisy

correction: iOS 15

Nov 12, 2024 1:21 AM in response to DenisOvidiu

I have the same problem with an HDMI to USB-C adapter. It worked fine before 15.1 but now I can't use my external display. Does anyone find a solution ?

Nov 13, 2024 11:26 AM in response to ZiaDaisy

ZiaDaisy wrote:

• correction: iOS 15

Correction: macOS 15. iOS is the operating system used by the iPhone.

Nov 14, 2024 11:12 AM in response to DenisOvidiu

Have the same issue in Macbook M1 pro in 15.1 with LG ultrafine 21,5” 4k. Randomly the monitor connects and disconnects many times during the day.

Nov 15, 2024 12:32 PM in response to Batalmasto

It didn't work for me either. Strange that I left the screen still with Lungo and nothing happened. When I started working more, the blinking started... Soooooo annoying...

Nov 20, 2024 8:28 PM in response to DenisOvidiu

Yes, I'm using Macbook Air M1 with LG 29 inch FHD + 21:9 monitor with Thunderbolt cable(for display) . After i updated to 15.1 immidiently ran into the same issue.

this must be fixed by Apple.