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flslflsl

macrumors newbie
Original poster
Feb 15, 2023
6
1
Hi, I have a Macbook Air 2020 M1, running Monterey OS.

I purchased a dock that allows me to connect to 2 extended monitors via HDMI. (link below)
https://en.j5create.com/products/jcd543

However, the problem is when it is hooked to 2 extended monitors, there is no video (Dark screen) when I try to play Netflix, only audio sound. It only works when I unplugged 1 of the monitors.

Does anyone know how to solve it? Is it because of the docking station I got? Thanks!!
 

Chancha

macrumors 68020
Mar 19, 2014
2,244
2,041
Without knowning definitely what’s going on, I suspect the hub’s way of producing more than one display must be breaking HDCP2.2 which Netflix expects on an external monitor / TV.

Have you tried unplugging one of the two displays to see what happens?
 

ArkSingularity

macrumors 6502a
Mar 5, 2022
928
1,130
Do videos from other sources also break the multi-monitor setup? I'm almost curious if there might be some sort of DRM issue with the way that the DisplayLink driver is handling video (it'd be odd, but if it's netflix-specific, I wouldn't be too surprised).
 

flslflsl

macrumors newbie
Original poster
Feb 15, 2023
6
1
Without knowning definitely what’s going on, I suspect the hub’s way of producing more than one display must be breaking HDCP2.2 which Netflix expects on an external monitor / TV.

Have you tried unplugging one of the two displays to see what happens?
Yes, it works with Netflix or other high definition video with only 1 monitor connected to the hub. Don’t know why
 

flslflsl

macrumors newbie
Original poster
Feb 15, 2023
6
1
Do videos from other sources also break the multi-monitor setup? I'm almost curious if there might be some sort of DRM issue with the way that the DisplayLink driver is handling video (it'd be odd, but if it's netflix-specific, I wouldn't be too surprised).
Yes, Netflix is one of the examples. Some other video formats don’t work either when connecting 2 displays. I don’t know how to check the video format type to be specified.
 

laptech

macrumors 601
Apr 26, 2013
4,083
4,417
Earth
Did you purchase the hub with a power supply because to run with multiple monitors would take a lot of power.
 

flslflsl

macrumors newbie
Original poster
Feb 15, 2023
6
1
Did you purchase the hub with a power supply because to run with multiple monitors would take a lot of power.
No I did not. I plugged in the power using regular usb-c charger.

1676477324070.jpeg
 

Chancha

macrumors 68020
Mar 19, 2014
2,244
2,041
So when you say "there is no video (Dark screen)", do you mean the entire 2nd screen goes black, or just the Netflix window / video area? So any of the playback bars or macOS interface itself are showing?
 

Chancha

macrumors 68020
Mar 19, 2014
2,244
2,041

I found a similar issue with users of DisplayLink hubs, you can check them all see if it helps but this particularly looks to be describing your case:
"It is a security issue with the way the usb adapter works. You are not allow to record streaming services. The adapter uses recording software to stream to a monitor and the internet thinks you are stealing and cut you off. once I stopped the Displaylink software all the streaming services worked fine."
 
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flslflsl

macrumors newbie
Original poster
Feb 15, 2023
6
1

I found a similar issue with users of DisplayLink hubs, you can check them all see if it helps but this particularly looks to be describing your case:
"It is a security issue with the way the usb adapter works. You are not allow to record streaming services. The adapter uses recording software to stream to a monitor and the internet thinks you are stealing and cut you off. once I stopped the Displaylink software all the streaming services worked fine."
You are absolutely correct. Once I disable the below DisplayLink software from recording, I was able to play the Netflix video. However, the other monitor would go completely dark full screen, which I was not able to use at all. By any chance, I would be able to solve it? Does it mean I need a new docking station? Many Thanks!
 

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SjoukeW

macrumors member
Jun 8, 2020
66
62
Netherlands
The M1 chip is able to drive 1 external monitor, no way to change that since it is hardware limited.
DisplayLink makes a display in software bypassing this limit, causing high cpu usage and all kind of limitations like no HDCP which is required for protected video-streams like Netflix. There is also no way to fix that.
 

JPack

macrumors G5
Mar 27, 2017
13,469
26,072
That dock uses screen mirroring to extend your display. It’s basically like DisplayLink. If you have a M1 or M2, it can only drive one external monitor. If a dock lets you drive more, it means it’s using software, which will break DRM. In short, you need a MacBook Pro if you want to fix this issue.
 

The Phazer

macrumors 68040
Oct 31, 2007
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London, UK

JayKay514

macrumors regular
Feb 28, 2014
181
161
The M1 chip is able to drive 1 external monitor, no way to change that since it is hardware limited.
DisplayLink makes a display in software bypassing this limit, causing high cpu usage and all kind of limitations like no HDCP which is required for protected video-streams like Netflix. There is also no way to fix that.
FWIW, the base M1 can support two displays, as on the original M1 Mac mini, but in the case of a MacBook, one of those displays is the built-in screen.

Laptops with the M1 Pro and Max can support multiple external displays, either with the lid open or closed (as long as you uncheck the preference to auto-sleep when the display is off, and have it connected to power, I think).
 

trevpimp

macrumors 6502a
Apr 16, 2009
697
301
Inside A Mac Box
The current MacOS and Apple hardware especially when using USBC/Thunderbolt adapters for external displays are more hard to understand than easy

In order to get signal from the Mac on to the External display(s) you gotta have the correct signals to and from both Input and Output,

You have to match the settings from your external display so that it finely matches your Mac display settings, its not just a plug and play thing now and days with Apples newer software coming out

Put it this way you can't have two different external displays with one being native 4k at 60z with another external display of 1440p 60hz at the same time, you have to correct the settings so that they match Resolution = Resolution Hertz = Hertz etc etc for EVERY Monitor coming out from one Mac
 

tstafford

macrumors 6502a
Sep 13, 2022
989
908
Indeed, you won't be able to buy a monitor that fixes this, it's a limitation of the M1 chip. Anything that provides two monitors is using a fairly dirty hack to do so that will break HDCP.
This. OP's issue is a limitation of Display Link. Known "issue". And I put issue in quotes because the real "issue" is that Apple limits the ability of the base M1 and M2 MBA to a single external display. Display Link is a hack IMHO. Works for some folks because of their needs but it isn't fully functional IMO.
 

amityweb

macrumors member
Oct 5, 2010
41
2
Wales
Which browser are you using? I have had similar issues when using Safari. I changed to Chrome and turned of Hardware Acceleration to watch Netflix on my external monitor.

See this post on the DisplayLink forum
After 1.6.1 install, video for Prime & Netflix does not work
This works for me! Brilliant.

I was in two minds whether to return my DisplayLink device because I sometimes watch TV when working and could not, so I would have to stop its software to do that making the 4th monitor redundant. But using Chrome and disabling graphics acceleration is working! I actually use Brave and it works in that too as its Chrome based.

Thanks a lot
 
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